What’s the BIG Deal?

Vitamin D is unique in the nutrient world in that it is the only vitamin made in the skin from exposure to sunlight, specifically from UVB rays. Our ancestors lived naked in the sun—hunting, gathering, fishing, and farming—for several hundred thousand years, daily producing up to 20,000 IU of vitamin D as a result. (This is over 30 times more than the US government's recommendation of 600 IU per day!) Our bodies developed based on a need for high levels of vitamin D; imagine that humans are much like plants that depend on the sun for growth and health. In fact, the human body has vitamin D receptors in every tissue and cell, and it influences the expression of more than 1,000 genes. In order to positively support health it is vital for the body to have optimal levels of vitamin D.

Over the years there has been one huge false assumption that has been made about vitamin D which has led to an epidemic of vitamin D insufficiency. This false assumption is that everyone receives more than sufficient amounts of D from sun exposure. But when was the last time you spent significant time in the sun, without slathering on sunscreen? Sunscreen blocks UVB rays from making vitamin D in the skin. Furthermore, depending on where you live, you may not be exposed to UVB rays during certain months of the year – think winter.

Latitude is key. If you live north of Austin, Texas, then you will not receive adequate UVB rays to make vitamin D from 2 to 5 months starting in November and lasting until March. Additionally, cloud cover and pollution block UVB rays so even at times of the year when there are sufficient amounts, they may be blocked and minimal vitamin D production occurs. Additionally, the darker your skin and the older you are, the less vitamin D you will produce from sun exposure. Black people make five to 10 times less vitamin D in their skin per minute of sun exposure than white people due to higher melanin pigmentation. Furthermore, if you carry excess body fat, the vitamin D you do make gets sequestered in fat cells and is not available for the body to use. And finally, approximately one-third of Americans have a genetic trait that reduces their vitamin D activity. For those with this trait, it takes more vitamin D to have a positive impact on health.

Think about this: The most significant change in the way that we live has been the amount of sunlight (UVB rays) we are exposed to on a daily basis and consequently, the amount of vitamin D we produce daily. Most of us work, play, and exercise inside; and when we do go outside, most of us put on sunscreen. The really significant reductions in our exposure to sunlight have occurred since the Industrial Revolution, and at the same time, the "diseases of civilization" like cardiovascular disease, diabetes, and cancer, seem to have greatly increased.

The prevalence of sub-optimal vitamin D levels in this country and around the world is astounding. A study that was published in the American Journal of Clinical Nutrition found that as many as 60 percent of whites and more than 90 percent of blacks had insufficient blood levels of vitamin D. In Denver, a city that sees a lot of sunshine, 74 percent of elderly people have suboptimal levels. In another study of senior patients, the average level of vitamin D was 18 ng/ml (nanograms per milliliter) when optimal is between 40 and 60. Those with the lowest D levels had the most depression and the worst performance on objective tests for dementia and cognitive function.

So, what’s the big deal? To understand the answer to this you have to first understand how the body processes and uses vitamin D. The first priority the body has for vitamin D is to regulate calcium levels, maintaining the body’s alkaline pH balance, an equilibrium that is critical for survival. This function is so vital that it takes priority.

How Full is Your Tank…?

If levels are low, (low levels are generally considered to be below 40 ng/ml) then most of the stored D you have will be used for this important function first. It is only when you have a full store of vitamin D that there is enough to regulate gene expression and support the health of every cell and tissue in the body. This is when you see all the health benefits that are associated with higher levels of vitamin D.

Numerous studies have shown that those with low levels of vitamin D significantly increase their risk of poor health. Conversely, numerous studies have shown that those with optimal levels support the health of a diverse range of functions including immune function, brain function and development, musculature/skeletal function, and even support for a healthy inflammatory response and healthy blood sugar levels.

So, what is an adequate level of vitamin D? Most vitamin D researchers now believe that the optimal range is between 50 and 80 ng/ml. Studies have shown that between 2,000 to 5,000 IU/day, in the form of D3 (which is the form our bodies naturally make and is the most bioavailable), are probably needed by most adults to bring levels into this range. A simple blood test, called the 25- hydroxy-vitamin D test, can determine if your levels are optimal. Vitamin D is not a miracle cure; however, because it is necessary for the proper functioning of so many systems, organs, tissues, and genes, improving health becomes much more difficult if you are deficient in, or have sub-optimal levels of, this important nutrient.

Statements of Nutritional Support* *This is not an exhaustive list of all the tissues, organs, systems, and structures that vitamin D supports, but is representative of the extensive role that vitamin D plays in human health.

1. Vitamin D is made in the skin when it is exposed to UVB light.
2. Wearing sunscreen blocks production of Vitamin D.
3. During certain times of the year, the winter months in the states of New Mexico, Texas, Colorado, Utah and Wyoming, UVB rays are blocked, so even if you spend time in the sun you will not produce any vitamin D.
4. The older you are the less vitamin D you produce from UVB exposure.
5. The darker your skin the less vitamin D you produce from UVB exposure.
6. If you carry excess body fat, the vitamin D you do make gets sequestered in fat cells and is not available for the body to use.
7. Over half of all Americans do not have optimal vitamin D levels.
8. About one-third of Americans have a genetic trait that reduces their vitamin D activity.
9. In Denver itself, 74% of elderly people have suboptimal levels of vitamin D.
10. Most vitamin D researchers agree that low levels of vitamin D are levels that are less than 40 ng/ml of 25-hydroxy-vitamin D.
11. Most vitamin D researchers agree that optimal levels of vitamin D are between 50 to 80 ng/ml or 25-hydroxy-vitamin D.
12. Vitamin D supports brain function and development.
13. There are vitamin D receptors in every tissue and cell in the human body.
14. Vitamin D regulates over 1000 different genes. Gene expression is the process in which information from a gene is transformed into biochemicals the body needs to function and stay healthy.
15. Vitamin D supports immune system function.
16. Vitamin D supports a healthy immune response, helping to make sure that the immune system does not over-react or under-react.
17. Vitamin D supports cardiovascular health.
18. Vitamin D supports positive moods, memory, and cognition.
19. Vitamin D supports bone health.
20. Vitamin D supports healthy blood sugar levels.
21. Vitamin D supports healthy C-reactive protein levels.
22. Vitamin D supports a balanced inflammatory response.
23. Vitamin D supports balance.
24. Vitamin D improves muscle strength.
25. Vitamin D supports respiratory health.
26. Vitamin D supports prostate health.
27. Vitamin D supports breast health.
28. Vitamin D may help slow aging.
29. Vitamin D supports joint health and function.
30. Vitamin D supports optimal health.
31. Vitamin D supports a healthy pregnancy.
32. Vitamin D is not a miracle cure; however, it is necessary for the functioning of so many systems, organs, tissues, and genes that improving health becomes much more difficult if you are deficient in or have sub-optimal levels of this important nutrient.

What is on the Shelf?

Vitamin D is available as either D3 (cholecalciferol) or D2 (ergocalciferol). D3 is what the skin produces when exposed to UVB rays and it is the form of D found in foods of animal origin. It is the preferred form to supplement with as it is the most bioavailable. D3 in supplements is either extracted from a natural source -- fish liver oil -- or it is a natureidentical synthetic product made from lanolin (lanolin is a waxy substance that comes from sheep’s wool). D3 from lanolin is made via the following process: lanolin alcohols are converted to a form of cholesterol and irradiated with UVB rays, which makes D3. If a supplement bottle lists D3 or cholecalciferol and does not give a source for it, such as fish liver oil, then it is made from lanolin.

D2 is a form of D made by some plants – fungi – when exposed to UVB rays. D2 In supplements is a nature-identical synthetic product made by irradiating fungi with UVB rays. Fungi contain fat-like substances called sterols when they are irradiated with UVB rays it turns into D2. As it is derived from plants, and not animals, it is considered vegan. This is not the preferred form to supplement with. It does not normally occur in the human body and it may be a weak agonist at the receptor site, meaning it may actually partially block vitamin D actions. And there is some evidence that it does not raise 25-hydroxy-vitamin D [25(OH)-D] levels as well as D3. Food Sources Can you get sufficient D3 from food? That depends on how much you like fish and fat. A serving of herring, oysters, catfish, mackerel and sardines plus generous amounts of butter, egg yolk, lard or bacon fat and 2 teaspoons cod liver oil (500 IU per teaspoon) will yield about 4,000 IU vitamin D (that is…ALL of these foods combined). Enjoy! In other words, getting sufficient amounts of D3 through your food is unlikely.

Vitamin D3

D3 (cholecalciferol) – is what your skin produces when exposed to UVB rays, and is the form found in foods of animal origin. It is the preferred form of vitamin D to supplement with, as it is most bioavailable..

Food Sources

Can you get sufficient D3 from food? That depends on how much you like fish and fat. A serving of herring, oysters, catfish, mackerel and sardines plus generous amounts of butter, egg yolk, lard or bacon fat and 2 teaspoons cod liver oil (500 IU per teaspoon) will yield about 4,000 IU vitamin D (that is…ALL of these foods combined). Enjoy! In other words, getting sufficient amounts of D3 through your food is unlikely.

Fortified foods provide most of the vitamin D in the American diet. For example, almost all of the U.S. milk supply is fortified with 100 IU/cup of vitamin D. Ready-to-eat breakfast cereals often contain added vitamin D, as do some brands of orange juice, yogurt, and margarine. In the United States, foods allowed to be fortified with vitamin D include cereal flours and related products, milk and products made from milk, and calcium-fortified fruit juices and drinks.