THE AMAZING STORY OF VITAMIN D3

There are several forms of Vitamin D but the most powerful in terms of health benefits is Vitamin D3.  Vitamin D2 is what is typcially added to, not found naturally in milk as most people think.  (Some more health-oriented brands of milk, like Lactaid, contain Vitamin D3.)

The high rate of natural production of vitamin D3 (cholecalciferol) in the skin is the single most important fact every person should know about vitamin D because it has such profound implications for the natural human condition.  For years, most of us wrongly assumed we'd be fine if we drank a little milk and took a multivitamin pill. Now, studies are reporting most of us are vitamin D deficient and those deficiencies may well be causing numerous illnesses, especially cancer.

Vitamin D is a steroid hormone precursor that has recently been found to play a role in a wide variety of diseases. Current research indicates vitamin D deficiency plays a role in causing seventeen varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, and periodontal disease—and it probably doesn't stop there, there is still much more research that needs to be done.

This does not mean that vitamin D deficiency is the only cause of these diseases, or that you will not get them if you take vitamin D. What it does mean is that vitamin D, and the many ways in which it affects a person's health, can no longer be overlooked by the health care industry nor by individuals striving to achieve and maintain a greater state of health. 

Vitamin D has long been recognized as vital to bone health because the body needs it to absorb calcium. But research has suggested that it may be good for a lot more than just bones. Ample intake of vitamin D may help fend off a wide range of conditions, including colon cancer, diabetes, and physical weakness in old age.

Meanwhile, another batch of studies has found that many people, especially as they grow older, have low levels of vitamin D in their blood. Our skin has an amazing ability to produce vitamin D when it’s exposed to sunlight, but with age, the skin becomes less productive. The problem is made worse by older people spending more time indoors.  Younger people absorb twice as much vitamin D than older people given the same exposure to sunlight.

Other factors that contribute to low vitamin D levels include living in the upper latitudes, where winters are long, and having darker skin. Rickets is the classic children’s disease caused by vitamin D deficiency. It has re-emerged as a problem in some African American communities.

Because of the evidence for shortfalls and the possibility of added benefits, some experts think the recommendations for vitamin D are set way too low. The vitamin D enthusiasts say adults should be getting at least 1,000 IU (International Units) a day.

The committees of experts convened by the Institute of Medicine to set daily nutrition requirements also calculate an upper limit (the technical term is Tolerable Upper Intake Level). It’s the too-much-of-a-good-thing level at which a normally healthful nutrient becomes possibly toxic.

An article published in the January 2007 American Journal of Clinical Nutrition reviewed dozens of vitamin D toxicity studies, including some that involved volunteers taking a whopping 100,000 IU a day. The authors concluded that the upper limit for daily intake of vitamin D could safely be set at 10,000 IU.

Still, a group of 15 nutrition experts cited the study in an editorial in the March 2007 issue of the same journal that called for an overhaul of vitamin D guidelines, although they stopped short of recommending definite amounts.

The experts — who include Dr. Walter C. Willett, chair of the Harvard School of Public Health’s nutrition department — noted that 400 IU doesn’t increase the amount of vitamin D circulating in the blood very much. Depending on how much a person started out with, they said a daily intake of about 2,000 IU  is necessary before blood levels get high enough for vitamin D to have its full disease-fighting effects.

Current vitamin D guidelines

Calcium supplements often include some vitamin D. And you can buy separate vitamin D pills that contain 1,000 IU or more. Some multi-vitamins have started using the more potent vitamin D3 (cholecalciferol), the form that is used most often to fortify milk and other foods, such as breakfast cereals.

Getting more sun exposure is another way to increase vitamin D levels, although doing so means changing the advice to avoid sun and wear sunscreen to protect against skin cancer and other forms of skin damage. Some analysis shows that any increase in skin cancer from adding a small amount of unprotected sun exposure would be offset by declines in other forms of cancer.

Some vitamin D researchers want to see “safe sun” recommendations that would actively encourage people to get 15 minutes or so of sun a few times a week — without sunscreen, which blocks the UV radiation that triggers vitamin D production in the skin.

The pressure to revise vitamin D recommendations is building. The American Cancer Society is preparing its first comprehensive set of guidelines for skin cancer prevention. So stay tuned. 
There’s been a lot of disappointing news about vitamins, but vitamin D, and particularly vitamin D3, stands out as a bright spot.