Several forms (vitamers) of vitamin D exist: D1, D2, D3 and D4. The two major forms are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D3 is the animal form; and vitamin D2 is the plant form.Vitamin D without a subscript refers to either D2 or D3 or both. These are known collectively as calciferol.
Chemically, the various forms of vitamin D are secosteroids, i.e., steroids in which one of the bonds in the steroid rings is broken. The structural difference between vitamin D2 and vitamin D3 is the side chain of D2 contains a double bond between carbons 22 and 23, and a methyl group on carbon 24.
Vitamin D2 and D3 are not biologically active -- they must be modified in the body to have any effect.
The active form of vitamin D is indeed a hormone and is known as 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or calcitriol. Both vitamin D2 and D3 have been commercially synthesized and both forms seem to be effective at maintaining blood levels of vitamin D in the body.
How Vitamin D Is Activated by the Sun
You may be wondering how Vitamin D is activated. Here are the sequence of steps:
Step #1: We convert cholesterol to 7-dehydrocholesterol, which is a precursor of vitamin D3.
Step #2: When we are exposed to UVB radiation, 7-dehydrocholesterol in the skin is converted to vitamin D3.
Step #3: Vitamin D3 must then be hydroxylated in the liver and the kidneys to become active. At this point, it can exert its endocrine effect.
Think you’re soaking up vitamin D through office/car windows? Wrong. Glass blocks virtually all UVB, preventing vitamin D from being made.
And sunscreen is similar. Applying sunscreen with an SPF of 15 will decrease the amount of vitamin D made in the body by about 99%.
Activated vitamin D has a serum half life of 2-3 weeks and its production in the skin is limited to 10,000-20,000 IU each day. Spending 20 minutes outside in the summer sun produces 100 times more vitamin D than government agencies say you need. And once serum levels reach 150 nmol/L, any excess is inactivated.
Vitamin D production via the sun can change throughout the year depending on where you live. If you live north of Atlanta, GA, you will make zero vitamin D from the sunlight between November and March. If you live below Atlanta, GA, you’ll be all right. It is possible to build some reserves of vitamin D, but these reserves won’t last longer than a few weeks.
Vitamin D in Food
Vitamin D is extremely rare in foods. It’s found in fish, cod liver oil, mushrooms, liver and eggs – but usually not in substantial amounts (except in cod liver oil).
Farmed varieties of fish contain very little vitamin D compared to the wild varieties. The only reason we even get vitamin D from foods like milk and cereal is because these foods are fortified with it — but, this vitamin D is synthetic.
Breast milk contains low amounts, with about 25 IU per liter.
Thus, getting enough vitamin D from whole foods is virtually impossible; it truly is the sunlight vitamin.
Fortification studies in adults show that consuming 100 – 1000 IU of vitamin D each day results in increased blood concentrations by 15 to 40 nmol/L. Other data with supplements indicate that for every 100 IU of vitamin D we ingest, we raise our blood levels by 2.5 nmol/L.
What should my blood levels be?
What really matters is our circulating 25-hydroxyvitamin D [25(OH)D] concentration. It lets us know how much vitamin D has been produced in our body from sun, food and supplements. Its half-life is 15 days. 1,25 (OH)2D is not a good indicator of vitamin D status, as it has a short half life of only 15 hours and levels in the blood are regulated tightly by hormones and minerals. 1,25 (OH)2D only starts to decline when a severe deficiency of vitamin D is present.
The most advantageous serum concentrations of 25(OH)D seem to begin at 75 nmol/L, with the optimal levels being between 90 and 100 nmol/L. Most people will be unable to reach these levels with an intake between 200 and 600 IU of vitamin D.
What intake is optimal?
An intake of greater than or equal to about 1000 IU may be needed for most of the population. For postmenopausal women and older men, 25(OH)D concentrations of less than 30 to 80 nmol/L are associated with negative health outcomes.
For infants at northern latitudes, studies suggest that 200 IU vitamin D2 per day may not be enough to prevent vitamin D deficiency. A meta-analysis in adults suggested that an increased intake of vitamin D3 of 100 IU per day was associated with an increase in circulating concentration of 25(OH)D of 1 to 2 nmol/L. A recent study on women in Maine found that 800 IU of vitamin D per day was enough to reach and maintain adequate blood levels during the winter (for most of the women).
What levels of vitamin D intakes are associated with adverse effects?
Most studies do not report adverse effects with vitamin D supplementation. One study showed an increased risk of kidney stones with supplemental intakes of 400 IU vitamin D3 (along with 1000 mg calcium) each day in women aged 50 to 79 years.
The Merck Manual notes:
Some studies suggest that intakes up to 10,000 IU per day have not been associated with adverse effects. If you take more than 10,000 IU per day of vitamin D orally for more than 6 months, you are definitely at risk of becoming vitamin D intoxicated. And remember, we cannot become vitamin D intoxicated from excessive sunlight.Taking very high daily doses of vitamin D—for example, 50 or more times the recommended daily allowance (RDA)—over several months can cause toxicity and a high calcium level in the blood (hypercalcemia).Early symptoms are loss of appetite, nausea, and vomiting, followed by excessive thirst, weakness, nervousness, and high blood pressure. Because the calcium level is high, calcium may be deposited throughout the body, particularly in the kidneys, blood vessels, lungs, and heart. The kidneys may be permanently damaged and malfunction, resulting in kidney failure.
Summary and Recommendations
Vitamin D deficiency is a disease of neglect. It’s up to us to get in the sun and/or use a quality supplement as needed. And the data seem to be pointing towards reaching “optimal” levels, not just “normal” levels.
Blood level classifications for 25(OH)D:
- Vitamin D intoxication: >/= 375 nmol/L
- Excess: >100 nmol/L
- Preferred range: 75-100 nmol/L (for treating heart disease and cancer)
- Sufficient range: 50-75 nmol/L (if you're relatively healthy)
- Mild deficiency: 25-50 nmol/L
- Moderate deficiency: 12.5-25 nmol/L
- Severe deficiency: <12 nmol="">12>
Based on the most recent research, the current recommendation for dosage via oral supplementation is 35 IU’s of vitamin D per pound of body weight. So for a 170-pound adult, the dose would be nearly 6,000 IU’s.
However, it’s important to realize that vitamin D requirements are highly individual, as your vitamin D status is dependent on numerous factors, such as the color of your skin, your location, and how much sunshine you’re exposed to on a regular basis.
So, although these recommendations may put you closer to the ballpark of what most people likely need, it is simply impossible to make a blanket recommendation that will cover everyone’s needs.
The only way to determine the correct dose is to get your blood tested since there are so many variables that influence your vitamin D status. The correct test your doctor needs to order is 25(OH)D, also called 25-hydroxyvitamin D, which is the better marker of overall D status. This is the marker that is most strongly associated with overall health.
Caution: Make certain that you get your vitamin D serum levels tested on a regular basis to prevent any toxicity or damage to your liver!
Vitamin D Deficiency
A diet deficient in vitamin D in conjunction with inadequate sun exposure causes osteomalacia (or rickets when it occurs in children), which is a softening of the bones. In the developed world, this is a rare disease.
However, vitamin D deficiency has become a worldwide issue in the elderly and remains common in children and adults. Low blood calcidiol (25-hydroxy-vitamin D) can result from avoiding the sun. Deficiency results in impaired bone mineralization and bone damage which leads to bone-softening diseases, including rickets or osteomalacia.
Consequently, vitamin D is vital for normal calcium metabolism, immunity, nervous system function, and bone density. But, due to our fear of the sun and because so many people live north of the equator, there is a major worldwide Vitamin D deficiency.
Note: Most people compensate by taking a Vitamin D supplement, but, recent studies show an ineffectiveness of most Vitamin D supplements as demonstrated by the increases in heart disease, cancer and diabetes (especially in African-Americans). (This will be discussed in more detail in a future post).
Medications can decrease activity of vitamin D in the body. These include anticonvulsants, bile acid sequestrants, GERD medications, corticosteroids and heparin. There is also some potential negative interactions with calcium channel blockers and diuretics, which can interfere with blood calcium levels.
People with dark skin may require 5-10 times the amount of sun exposure to produce adequate vitamin D, compared to someone with light skin pigmentation.
Why is Vitamin D So Important?
All of your body’s organs and cells have receptors for vitamin D, meaning that vitamin D communicates all around your body. Your cells use vitamin D to directly regulate your genes, making it one of the most powerful compounds in human health. One study with 2,100 female twins showed that having adequate vitamin D extends life by five years. This is because vitamin D prevents excessive wear and tear to the telomers that are attached to the ends of your chromosomes and enable cell division; telomeres determine potential cell lifespan. This is truly a new era of nutritional science.
Vitamin D must be converted into its biologically active form (1,25(OH)2D) before it goes to work. Your kidneys are the main organs that do this for your body as a whole, but many cells have the enzymes to directly activate vitamin D. For example, cells lining your lungs and digestive tract can activate vitamin D to help fight infection. The vitamin D receptors (VDRs) around your body are capable of binding both the active and inactive forms of vitamin D. Cells that activate vitamin D can also inactivate it, forming a convenient system of self-regulation based on a variety of needs.
Once vitamin D is active in cells it has one main job: activating genes. In other words, vitamin D’s basic role in your body is to help regulate its functions at the level of gene transcription. Because so many different tissues and types of cells use vitamin D, it can be assumed that this is a fundamental need for survival.
Your body places a high value on vitamin D and has made provisions to store it in your liver and the lining of your digestive tract5. This vitamin D savings account can be called into action when needed, such as during the long winter months. It is interesting that vitamin D deficiencies in your liver or digestive tract are associated with the poor health6 of both organ systems.
When your skin makes vitamin D the vitamin D turns on antioxidants within your skin to deactivate the free radicals coming from the sun’s UV radiation. This is a natural defense mechanism (a built in sunscreen). New science shows that only nine percent of the population has vitamin D receptors that don’t do a good job of this. It is ridiculous to make 100 percent of the population think that routine sun exposure is a major health risk when such advice applies mostly to a small group.
Studies also reveal that low vitamin D levels in the body are associated with:
Increased loss of muscle strength and mass as we age
Increased risk of cancers
Lower levels of immunity
Higher blood pressure
The development of neurological disorders
The development of diabetes
Despite the importance of vitamin D, it’s estimated that anywhere from 60% to 80% of the U.S. population is vitamin D deficient. It’s likely worse among people with darker skin living in northern zones, as their skin pigmentation screens out the relatively limited sunlight more effectively.
Vitamin D levels can also be affected by age and body fat levels. As we age, our ability to make vitamin D is reduced by 75%. Furthermore, vitamin D can get trapped in body fat, leading to a 55% reduction in blood levels for those who are over-fat.
Research on vitamin D, including large-scale clinical trials, is ongoing. But, the preliminary findings appear to indicate that there are multiple health benefits of Vitamin D.
According to one large-scale study, optimal Vitamin D levels can slash your risk of cancer by as much as 60 percent. Keeping your levels optimized can help prevent at least 16 different types of cancer, including pancreatic, lung, ovarian, prostate, and skin cancers.
The many potential and projected health benefits of Vitamin D include the following:
Autoimmune disease: Vitamin D has a dampening effect on excessive and inappropriate behavior of immune cells; it helps reduce the amount of inflammation produced by immune cells. A vitamin D deficiency may be an underlying and possibly causative issue for almost any autoimmune problem. A theory can be put forth that vitamin D adequacy is required to prevent your immune system from going into an improper hyperactive and excessively inflammatory state – a problem that is at least a part of all diseases of aging.
Studies show vitamin D’s ability to help prevent as well as improve issues such as arthritis, autoimmune type 1 diabetes, and inflammatory bowel disease.
Individuals with any autoimmune disease should have their vitamin D levels tested by their physician; these should be corrected as a first step in seeking to improve any problem.
It is interesting that vitamin D helps both a lacking and hyperactive immune system work well. A key theme of nutrition is that it works in your body to promote efficiency of healthy function. In the case of vitamin D it not only boosts underperformance, bit it also quiets down excessive and improper activity. Obviously, no drug has such intelligence.
Although tentative data link low levels of vitamin D to asthma, evidence to support a beneficial effect from supplementation is inconclusive.
Bone health: In general, evidence supports that vitamin D can help with osteoporosis.
For older people with osteoporosis, taking vitamin D with calcium may help prevent hip fractures, but it also slightly increases the risk of stomach and kidney problems.
Athletes who are vitamin D deficient are at an increased risk of stress fractures and/or major breaks, particularly those engaging in contact sports. The greatest benefit with supplementation is seen in athletes who are deficient (25(OH)D serum levels <30 ng.="" p="">
Brain Health: Animals research has shown that low vitamin D during pregnancy caused brain abnormalities similar to those seen in patients with schizophrenia. Because vitamin D is involved with gene transcription in the evolving nervous system, a lack of it is bound to cause some problems.
Cancer: One of the main functions of vitamin D is to tell your genes what to do. Many of these functions relate to cell growth and division. For example, adequate vitamin D is crucial to the healthy growth of your skin and hair. In fact, a lack of vitamin D can result in an autoimmune reaction that makes your hair fall out or in disruptions to consistent skin pigmentation.
Cancer problems imply that cell division has gotten out of control in an inappropriate way. Just as vitamin D is needed by immune cells so they don’t become hyperactive and inappropriate, so it is that vitamin D may be needed to help regulate cell growth and differentiation to keep it in a healthy condition.
A number of precise cell growth factors are favorably influenced by vitamin D, which is likely to have benefit for many kinds of cancer. Current vitamin D cancer research has tended to focus on colon, breast, and prostate cancer.
One aspect of the current research shows that vitamin D is a partner in the antioxidant defense system of cells, helping clear them of free radicals and thereby protecting them from DNA damage that can lead to mutation. Interestingly, vitamin D is smart enough not to protect cancer cells. That finding, along with earlier work, led this research group to claim, “Our findings reflect what we see in those studies and demonstrate that vitamin D not only can be used as a therapy for prostate cancer, but it can also prevent prostate cancer from happening.”
Some of the newer colon cancer research finds that vitamin D turns on death signals in colon cancer cells, and works synergistically with calcium to help prevent colon cancer cells from spreading.
A definitive German study has now proven that low levels of vitamin D in premenopausal women are associated with an increased risk in breast cancer. Compared to the women with the highest vitamin D, the increased risk ranged from 45 percent - 68 percent, depending on the amount of deficiency.
Vitamin D may help diminish the risk of development of certain cancers including colon cancer.
Is Vitamin D the New Silver Bullet for Cancer?
Intake of vitamin D3 and calcium could potentially prevent 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer annually in the United States and Canada, according to a complex computer prediction model.
This model also predicted that 75 percent of deaths from these cancers could be prevented with adequate intake of vitamin D3 and calcium.
Theories linking vitamin D to certain cancers have been tested and confirmed in more than 200 epidemiological studies, and understanding of its physiological basis stems from more than 2,500 laboratory studies, according to epidemiologist Cedric Garland, DrPH, professor of family and preventive medicine at the UC San Diego School of Medicine.
Dr. Garland is widely regarded as the leading epidemiologist on vitamin D and its relation to health. He led one of the latest studies on vitamin D for cancer prevention and proposed a new model of cancer development -- dubbed DINOMIT-- that is centered on a loss of cancer cells' ability to stick together.
The model is a departure from the older model of cancer development, which centers on genetic mutations as the earliest driving forces behind cancer. According to Dr. Garland:
"The first event in cancer is loss of communication among cells due to, among other things, low vitamin D and calcium levels. In this new model, we propose that this loss may play a key role in cancer by disrupting the communication between cells that is essential to healthy cell turnover, allowing more aggressive cancer cells to take over."
Vitamin D’s protective effect against cancer works in multiple ways, including:
• Increasing the self-destruction of mutated cells (which, if allowed to replicate, could lead to cancer)30>
• Reducing the spread and reproduction of cancer cells
• Causing cells to become differentiated (cancer cells often lack differentiation)
• Reducing the growth of new blood vessels from pre-existing ones, which is a step in the transition of dormant tumors turning cancerous
Doctors have known that low levels of vitamin D are linked to certain kinds of cancers as well as to diabetes and asthma, but new research also shows that the vitamin can kill human cancer cells.
Another recent study suggested that vitamin D can help prevent cancer. The researchers write: “Raising the minimum year-around serum 25(OH)D level to 40 to 60 ng/mL (100–150 nmol/L) would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three fourths of deaths from these diseases in the United States and Canada… Such intakes also are expected to reduce case-fatality rates of patients who have breast, colorectal, or prostate cancer by half. There are no unreasonable risks from intake of 2000 IU per day of vitamin D3 , or from a population serum 25(OH)D level of 40 to 60 ng/mL.”
One review in 2014 suggested that vitamin D3 may slightly decrease the risk of death from cancer (one fewer death in 150 people over 5 years), but concerns with the quality of the data were noted.
2015 research vitamin D has been effective at controlling low grade prostate cancers after diagnosis, without the need for orthodox treatment. All of which really does make a nonsense of health bodies and cancer charities who tell you to stay out of the sun because you might get skin cancer!
In 2014 vitamin D was shown to make certain chemo drugs work better, and researchers in America are proposing to use it as part of a hormone therapy package with breast cancer patients.
Cancer patients with high vitamin D levels live longer.
Why vitamin D matters for cancer patients.
Cardiovascular disease: Vitamin D provides health benefits to the cardiovascular system by helping to lower blood pressure and reduce the risk of stroke, cerebrovascular disease, cardial infarction, or ischaemic heart disease.
Researchers at the University of Michigan have nicknamed vitamin D “the heart tranquilizer” because it helps keep your heart from working so hard and swelling in size. Their findings indicate that vitamin D can help prevent heart failure.
Vitamin D has also been shown to improve blood flow in your extremities, helping improve what researchers call peripheral artery disease (PAD). Researchers evaluated 4,839 U.S. adults and found those with the best vitamin D levels had the least amount of PAD.
Vitamin D Helps Prevent Heart Disease, Diabetes
Further, middle aged and elderly people with high levels of vitamin D could reduce their chances of developing heart disease or diabetes by 43 percent, according to researchers.
A systematic literature review of the relationship between vitamin D and cardiometabolic disorders looked at 28 studies including nearly 100,000 participants.
The studies revealed a significant association between high levels of vitamin D and a decreased risk of developing cardiovascular disease, type 2 diabetes, and metabolic syndrome.
All studies included were published between 1990 and 2009, with the majority published between 2004 and 2009. Half of the studies were conducted in the United States, eight were European, two studies were from Iran, three from Australasia and one from India.
Dementia: A systematic review of clinical studies shows an association between low vitamin D levels, cognitive impairment, and a higher risk of developing Alzheimer's disease.
Depression: Clinical trials of vitamin D supplementation for participants with clinically significant depressive symptoms or depressive disorder had a moderate effect.
Low vitamin D is associated with depression in older Americans.
An interesting study compared vitamin D levels in older Americans to those with Parkinson’s33 and Alzheimer’s disease. Patients with Parkinson’s were 55 percent more likely to be low in vitamin D.
Thus, if your hands are a bit shaky and/or your mood is a bit off then maybe you could use a little more vitamin D.
Diabetes: Vitamin D is believed to help improve the body’s sensitivity to insulin – the hormone responsible for regulating blood sugar levels – and thus reduce the risk of insulin resistance, which is often a precursor to type 2 diabetes.
Some scientists also believe this vitamin may help regulate the production of insulin in the pancreas.
Vitamin D levels should ideally be between 20-56 ng/ml (50-140 nmol/l)*, with anything below 20 ng/ml considered deficient.
However, it is now known that raising the amount of vitamin D in your body to around 60-80 ng/ml can help keep blood glucose levels under control, which is vital for people with diabetes.
*Note: The correct level of vitamin D varies from person to person. The only way to be sure that your vitamin D levels are where they should be is to request a 25-hydroxyvitamin D, or 25(OH)D, blood test from your GP. Ideally your blood level of 25 OH D should be 60ng/ml.
Immune system: The front line troops (immune cells) of your innate immune system use vitamin D to help mount an immune response against invading bacteria. These immune cells use vitamin D to produce a germ-killing compound called cathelicidin. Your immune cells then release cathelicidin to kill bacteria. This is a process that does not work if there is a lack of vitamin D. Its bacteria killing properties have been known for some time and have even been used to help kill tuberculosis.
In general, vitamin D functions to activate the innate and dampen the adaptive immune systems. Deficiency has been linked to slow wound healing and increased risk of viral infections, including HIV and influenza. Low levels of vitamin D appear to be a risk factor for tuberculosis, and historically it was used as a treatment.
According to research from the University of Copenhagen in 2010, when T-lymphocytes of the immune system come across a pathogen, the first thing they do is bind to a vitamin D molecule to ´activate´ themselves.
Certain immune cells (B cells and T cells) have vitamin D receptors and can respond to calcitriol whereas some phagocytes can convert 25-hydroxyvitamin D into calcitriol. This suggests that phagocytes may communicate with T and B cells through calcitriol.
Recent studies covered in Cancer Watch suggest that the action of vitamin D is enhanced by vitamin K. Most adults are increasingly short of both D and K vitamins.
2012 research from the University of Carolina showed that children with low blood levels of vitamin D were more likely to become critically ill.
T Cell Activation: Scientists from the Department of International Health, Immunology and Microbiology have discovered that Vitamin D is crucial to activating our immune defenses and that without sufficient intake of the vitamin, the killer cells of the immune system - T cells - will not be able to react to and fight off serious, life-threatening infections in the body.
For T cells to detect and kill foreign pathogens such as clumps of bacteria or deadly viruses, the cells must first be ‘triggered' into action and ‘transform' from inactive and harmless immune cells into killer cells that are primed to seek out and destroy all traces of a foreign pathogen.
The researchers found that the T cells rely on vitamin D in order to activate and they would remain dormant, ‘naïve' to the possibility of threat if vitamin D is lacking in the blood.
T cells that are successfully activated transform into one of two types of immune cell. They either become killer cells that will attack and destroy all cells carrying traces of a foreign pathogen or they become helper cells that assist the immune system in acquiring "memory". The helper cells send messages to the immune system, passing on knowledge about the pathogen so that the immune system can recognize and remember it at their next encounter and launch a more efficient and enhanced immune response. T cells form part of the adaptive immune system, which means that they function by teaching the immune system to recognize and adapt to constantly changing threats.
Obesity: Vitamin D levels are low in obese adults. It is well known that vitamin D helps stimulate the release of insulin from your pancreas. A lack of vitamin D drastically increases the risk for type 1 diabetes and is likely involved with the insulin and leptin resistance that eventually causes type 2 diabetes. A lot more work is needed in this area to fully understand these issues, but here is what we know so far:
The further you live from the equator the higher your risk for getting type 1 diabetes. If you live in Finland your risk goes up four hundredfold. How vitamin D protects the beta cells of your pancreas is not known, but it likely dampens inflammatory immune signals and boosts antioxidant protection – as it has been shown to do in other areas of your body.
Pooled data from existing studies shows that a child supplemented with vitamin D is 30 percent less likely to develop type I diabetes even as an adult. In a very large Finnish study those infants and children who consistently took 2,000 IU of vitamin D per day had a 78 percent reduced risk of type 1 diabetes.
Many overweight people are low in vitamin D. Correcting vitamin D deficiency has been shown to improve insulin resistance, which gives vitamin D a role in also helping prevent type 2 diabetes (the most common form).
New research shows that vitamin D is metabolically active within your stored fat, although we don’t know exactly what it is doing. We know from earlier research that vitamin D helps reduce excess leptin from fat. High leptin lowers another fat hormone called adiponectin, which we know must be at higher levels to prevent insulin resistance and type 2 diabetes. While there is a lot more about this to learn, it appears that adequate vitamin D is helpful for healthy blood sugar and fat metabolism.
If you are struggling with weight or the health of your pancreas it may be another sign that some extra vitamin D is needed.
Weight Loss: Studies have shown that good vitamin D status helps to reduce parathyroid hormone (PTH) levels, which in the long-term may promote weight loss and reduce risk of obesity, which is a major risk factor for type 2 diabetes.
Regulate appetite: Vitamin D can increase your body’s levels of the hormone leptin, which controls body fat storage and triggers the sensation of satiety, giving the feeling of having eaten enough and thus lowering hunger levels.
Reduce belly fat: An increase in vitamin D can help lower levels of cortisol, a stress hormone produced in the adrenal glands. Cortisol is involved in a number of important functions, including the body's response to stress and regulation of blood pressure. But higher and more prolonged levels of the hormone in the blood can lead to increased abdominal (or visceral) fat, which is linked to various health conditions including diabetes type 2.
More Evidence of Vitamin D Health Benefits
The evidence keeps growing that vitamin D is a superstar for your health. Here is a website that has compiled more than 800 top references proving beyond a doubt that Vitamin D is a necessity in fighting heart disease, diabetes, cancer, autoimmune diseases, obesity, etc..
Vitamin D Deficiency
Most of us don't have an obvious Vitamin D deficiency. However, our Vitamin D levels may not be high enough to fight diseases such as heart disewase, diabetes and cancer.
Unfortunately, most physicians aren’t aware of this problem and don’t understand the problems it can cause. Vitamin D Research is finding that Low Vitamin D is a widespread problem that has a lot of serious consequences of which we are just beginning to understand.
Scientists are just beginning to put all of the pieces together, but the first symptoms of Vitamin D deficiency could be:
-- Cancer (Bone, Breast, Colon, Lung, Ovarian, Prostate)
-- Chronic Fatigue
-- Colds and Flu Symptoms
-- Heart Failure and Cardiomyopathy
-- High Cholesterol
-- Multiple Sclerosis
-- Periodontal Disease and Cavities
While these are complicated diseases and there are obviously other factors involved in any individual’s risk, it’s true that a common risk factor for each and every one of these diseases happens to be a Low Vitamin D level!!
While the Low Vitamin D levels found in these diseases doesn’t necessarily mean that they cause these diseases, there must be some connection. And, if you take into account that low Vitamin D weakens the Immune System and some most diseases are related to a failed immune response – you can start to see that some of these diseases could be associated with a Vitamin D deficiency.
Vitamin A and Vitamin D Activation
One of the reasons why we may not be reaping the tremendous health benefits of Vitamin D is due to our bodies not having enough Vitamin A. Most of us rely on getting our Vitamin A by eating yellow and orange vegetables, which contain carotenoids that are converted to Vitamin A. Unfortunately, recent studies indicate that our bodies are converting less than 20% of the carotenoids to Vitamin A.
Vitamins A and D are both precursors to active hormones that regulate the expression of genes. The body possesses certain enzymes that convert each of these in a two-step process to their active forms:
-- Vitamin A is converted to retinal and then to active retinoic acid
-- Vitamin D is converted to calcidiol and then to active calcitriol.
While directly consuming either retinoic acid or calcitriol would be unnatural, consuming vitamins A and D, together, as in cod liver oil, is perfectly natural. Remember when your mother gave you a teaspoon of cod liver every morning before you went to school? (yuck!)
In order for vitamin D to activate the expression of its target genes, it must bind to the vitamin D receptor (VDR) and then combine with the retinoid X receptor (RXR), which is activated by a particular form of vitamin A called 9-cis retinoic acid. Researchers recently showed that vitamin D can only activate target genes when its receptor is activated by vitamin A. In the absence of vitamin A, molecules called “corepressors” bind to the VDR/RXR complex and prevent vitamin D from functioning!
The RXR and its activator retinoic acid partner up not only with the vitamin D receptor, but also with the receptors for steroid hormones, thyroid hormone, and most other nuclear receptors.
Researchers have shown that retinoic acid interferes with the ability of vitamin D to stimulate the production of osteocalcin, a vitamin K-dependent protein involved in organizing the mineralized matrix of bone. When scientists incubate cells with activated vitamin D and retinoic acid, the two hormones stimulate the production of osteocalcin with remarkable synergy.
EMBO Rep. 2006 Oct;7(10):1030-4. Epub 2006 Aug 25.
The retinoid X receptor ligand restores defective signalling by the vitamin D receptor.
Sánchez-Martínez R1, Castillo AI, Steinmeyer A, Aranda A.
Vitamin D-Dependent Recruitment of Corepressors to Vitamin D/Retinoid X Receptor Heterodimers.
Ruth Sánchez-Martínez†, Alberto Zambrano†, Ana I. Castillo and Ana Aranda
Vitamin D Supplementation
Most people take a Vitamin D supplement in the form of a tablet or capsule because of the difficulty of getting enough sunlight.
However, we do not reap the benefits of Vitamin D because of several mistakes that we make when taking Vitamin D supplements.
In fact, recent studies show an ineffectiveness of most Vitamin D supplements as demonstrated by the increases in heart disease, cancer and diabetes (especially in African-Americans, who are the Number 1 or Number 2 risk group for many of these lifestyle-driven diseases).
Vitamin D Supplement Mistakes
Mistake #1: Taking supplements that are synthetic.
Mistake #2: Taking Vitamin D2 instead of Vitamin D3.
Mistake #3: Taking the wrong dosage.
Mistake #4: Not getting enough Vitamin A from our diet.
Mistake #5: Taking the wrong form of Vitamin A or avoiding Vitamin A supplements because of the toxicity issue.
Mistake #6: Not eating foods that contain Vitamin K2 or not taking a Vitamin K2 supplement.
FYI: Vitamin K2 helps to ensure that calcium does not end up in your arteries, which can lead to atherosclerosis. .
Vitamin D does so many things helpful to your health that you absolutely do not want to run short of it. Government recommendations for dietary intake of vitamin D are too low, especially for the winter months when vitamin D is so important to the function of your immune system.
Vitamin D has been found to influence over 200 genes, highlighting links to multiple diseases.
The Overlooked Importance of Vitamin D Receptors
Vitamin D and Cardiovascular Health
Vitamin D and the Immune System
- ^ Vitamin D is Vital to Bone Health Nat Clin Pract Rheumatol. Wolff AE, Jones AN, Hansen KE; Medscape.
- ^ Vitamin D Deficiency Pandemic Mol Aspects Med. Holick MF.
- ^ Adequate Vitamin D Extends Lifespan American Jounal of Clinical Nutrition Richards JB, Valdes AM, Gardner JP, Paximadas D, Kimura M, Nessa A, Lu X, Surdulescu GL, Swaminathan R, Spector TD, Aviv A.
- ^ How Vitamin D Works in Your Body J Clin Endocrinol Metab. Bikle D.
- ^ Vitamin D is Stored in Multiple Locations Along Your Digestive Tract Eur J Drug Metab Pharmacokinet. Stumpf WE.
- ^ Vitamin D Lacking In Serious Liver and Digestive Problems 73rd Annual Scientific Meeting of the American College of Gastroenterology.
- ^ Vitamin D Protects Against UV Damage J Steroid Biochem Mol Biol. Dixon KM, Deo SS, Wong G, Slater M, Norman AW, Bishop JE, Posner GH, Ishizuka S, Halliday GM, Reeve VE, Mason RS.
- ^ Skin Cancer a Risk for Only 9% Cancer. Mocellin S, Nitti D
- ^ Vitamin D Intake of 2000 IU May Be Needed Anthony Norman
- ^ Vitamin D at 2000 IU Needed for Children J. Clin. Endocrinol. Metab. Joyce Maalouf, Mona Nabulsi, Reinhold Vieth, Samantha Kimball, Rola El-Rassi, Ziyad Mahfoud, and Ghada El-Hajj Fuleihan.
- ^ 400 IU of Vitamin D Is Not Enough for Kids Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA. Rajakumar K, Fernstrom JD, Holick MF, Janosky JE, Greenspan SL.
- ^ 800 IU Vitamin D Is Not Enough for Pregnancy Clin Endocrinol (Oxf). Yu CK, Sykes L, Sethi M, Teoh TG, Robinson S.
- ^ Mom’s Vitamin D Status Affects Baby’s Dental Health 86th General Session of the International Association for Dental Research. R. Schroth, et al.
- ^ Young Men Need 700-800 IU of Vitamin D in the Winter J Bone Miner Res. Viljakainen HT, Väisänen M, Kemi V, Rikkonen T, Kröger H, Laitinen E, Rita H, Lamberg-Allardt C.
- ^ Mayo Clinic Likes Vitamin D Mayo Clinic Press Release
- ^ How Vitamin D Works in Your Body J Clin Endocrinol Metab. Bikle D.
- ^ Vitamin D Helps Skin Immunity Journal of Allergy & Clinical Immunology Richard Gallo, et al.
- ^ Vitamin D Helps Lung Immunity Journal of Immunology Sif Hansdottir, et al.
- ^ How Vitamin D Works in Your Body J Clin Endocrinol Metab. Bikle D.
- ^ Vitamin D and Prostate Cancer International Journal of Cancer Yi-Fen Lee, et al.
- ^ Vitamin D and Calcium in the War on Colon Cancer American Association for Cancer Research meeting in San Diego.
- ^ Vitamin D and Breast Cancer Risk Int J Cancer. Abbas S, Chang-Claude J, Linseisen J.
- ^ Vitamin D and Type I Diabetes Diabetologia Cedric F. Garland, et al.
- ^ Vitamin D Cuts Risk for Type I Diabetes BMJ
- ^ Vitamin D Reduces Type I Diabetes by 78% Lancet. Hyppönen E, Läärä E, Reunanen A, Järvelin MR, Virtanen SM.
- ^ Insulin Resistance and Vitamin D Curr Diab Rep. Holick MF.
- ^ Vitamin D is Active in Stored Fat J Steroid Biochem Mol Biol. Li J, Byrne ME, Chang E, Jiang Y, Donkin SS, Buhman KK, Burgess JR, Teegarden D.
- ^ Vitamin D Reduces Leptin from Fat J Endocrinol. Menendez C, Lage M, Peino R, Baldelli R, Concheiro P, Diéguez C, Casanueva FF.
- ^ Vitamin D Protects Your Heart Journal of Cardiovascular Pharmacology Robert Simpson, Peter Mancuso, Ayesha Rahman, Stephen D. Hershey, Loredana Dandu, and Karl A. Nibbelink..
- ^ Vitamin D Helps Your Circulation American Heart Association’s Arteriosclerosis, Thrombosis and Vascular Biology Annual Conference 2008. Michal Melamed, et al.
- ^ Schizophrenia and Prenatal Vitamin D Status
- ^ Vitamin D and Depression Arch Gen Psychiatry. Witte J. G. Hoogendijk, et al.
- ^ Vitamin D and Parkinson Disease Arch Neurol. Evatt ML, Delong MR, Khazai N, Rosen A, Triche S, Tangpricha V.
Note: For most of these ailments, further research is needed to determine if the association represents a cause and effect relationship.
FYI: Vitamin D2 was chemically characterized in 1931. In 1935, the chemical structure of vitamin D3 was established and proven to result from the ultraviolet irradiation of 7-dehydrocholesterol.