Vitamin D, once thought to influence little more than bone diseases such as rickets and osteoporosis, is now recognized as a major player in overall human health. Most recently, new studies suggest that your vitamin D status can even help or hinder your weight management, which I'll review below.

It's a tragedy that dermatologists and sunscreen manufacturers have done such a thorough job of scaring people out of the sun. Their widely dispersed message to avoid the sun as much as possible, combined with an overall cultural trend of spending more time indoors during work and leisure time has greatly contributed to the widespread vitamin D deficiency seen today.

Vitamin D is actually not a vitamin at all but a potent neuroregulatory steroidal hormone, shown to influence about 10 percent of all the genes in your body. We now know this is one of the primary reasons it can impact such a wide variety of diseases, including:

Cancer--Hypertension--Heart disease--Autism--Obesity--Rheumatoid arthritis--Diabetes 1 and 2--Multiple Sclerosis--Crohn's disease--Colds--Flu--Tuberculosis Septicemia--Aging--Psoriasis--Eczema--Insomnia--Hearing lossex--Muscle pain--Cavities--Periodontal disease--Athletic performance--Macular degeneration--Myopia--Pre eclampsia--Seizures--Fertility--Asthma--Cystic fibrosis--Migraines--Depression--Alzheimer's disease--Schizophrenia

Vitamin D Deficiency Contributes to Weight Gain in Older Women

A new study of more than 4,600 women age 65 and older shows that having low vitamin D levels can contribute to mild weight gain.1 Previous research has already shown that obese individuals tend to have low vitamin D levels. Women who had insufficient levels of vitamin D gained about two pounds more compared to those with adequate blood levels of vitamin D during the 4.5-year long study. Those with insufficient levels also weighed more at the outset of the study. According to

"The study can't say whether low vitamin D is causing the weight gain or just reflecting it. 'The study is the first step that we need to evaluate whether vitamin D might be contributing to weight gain,' [lead researcher Erin] LeBlanc says. But there are some theoretical ways that low vitamin D could contribute to weight gain, she says. Fat cells do have vitamin D receptors. 'Vitamin D could affect where fat cells shrink or get bigger.'

Here, vitamin D levels above 30 nanograms per milliliter (ng/ml) were considered "sufficient." As I've previously reported, based on the latest vitamin D research this is still far below optimal, so it's difficult to say what the outcome might be if you were to actually optimize your levels by getting your blood level above 50 ng/ml. Still, despite this low "sufficient" level, 80 percent of the women in the study were found to have insufficient levels, meaning below 30 ng/ml. This gives you an idea of just how widespread this problem really is.

Vitamin D Deficiency Common among Adolescents Evaluated for Weight Loss Surgery. A second study found that more than half of obese adolescents seeking weight loss surgery are deficient in vitamin D. Eight percent were found to have severe deficiencies, and teens with the highest BMIs were the most likely to be vitamin D deficient. Less than 20 percent had adequate vitamin D levels. The research correlates with previous studies showing vitamin D deficiency in adults seeking bariatric surgery. (The results were presented at The Endocrine Society's 94th Annual Meeting in Houston on June 26.)According to Science Daily:3

"'This is particularly important prior to bariatric surgery where weight loss and decreased calcium and vitamin D absorption in some procedures may place these patients at further risk,' said study lead author Marisa Censani, M.D., pediatric-endocrinology fellow at Columbia University Medical Center, in New York City.
...'These results support screening all morbidly obese adolescents for vitamin D deficiency, and treating those who are deficient, particularly prior to bariatric procedures that could place these patients at further risk,' Censani said."
In the US, bariatric weight-loss surgery, such as gastric bypass surgery, is becoming increasingly common among all age groups, including children. Gastric-bypass surgery involves surgically removing a section of your stomach, which limits the amount of food it can hold. However, this procedure is fraught with risks, and maintaining proper nutrition post-surgery is a common challenge that can result in malabsorption syndromes. It's important to remember that vitamin D, as well as vitamin A, E, and K are fat-soluble, and need a certain amount of healthy fat to be absorbed properly.

What is the OPTIMAL Level of Vitamin D?
The ideal way to optimize your vitamin D levels is through adequate, safe sun exposure or using a safe tanning bed. However, whether you're tanning or using a vitamin D supplement, it's important to get your vitamin D levels tested to ensure you're within the optimal range of 50-70 ng/ml. For more information about proper sun exposure and how to determine whether you can actually get enough vitamin D from the sun at your location during different times of year, please see this previous article. As mentioned earlier, the "normal" 25-hydroxyvitamin D lab values are typically between 20-56 ng/ml. "Sufficient" levels are often considered to be around 30 ng/ml, as in the studies above.
However, this range is too broad to be ideal, and too low to support optimal health.
Beware that any level below 20 ng/ml is considered a serious deficiency state, increasing your risk of as many as 16 different cancers and autoimmune diseases like multiple sclerosis and rheumatoid arthritis. The OPTIMAL value that you're looking for is 50-70 ng/ml. Keeping your level in this range, and even erring toward the higher numbers in this range, is going to give you the most protective benefit. 

But how do you get within that range?
While vitamin D experts typically recommend 35 IU's of vitamin D per pound of body weight, it's important to understand that there's no one dosage recommendation that will be applicable for everyone. The only way to determine how much vitamin D you really need is to get your levels tested at regular intervals to make sure you're staying within the optimal range of 50-70 ng/ml, and adjust your dosage accordingly. If you're supplementing, you may find that you don't need to supplement during the summer, if you're getting sufficient amounts of sun exposure, for example. But you won't know if you don't get your levels tested. What is the OPTIMAL Way to Obtain Vitamin D?
There is simply no question in my mind that you were designed to receive your vitamin D from ultraviolet B exposure on your exposed skin and ideally this should come from the sun. For virtually the entire history of the human race this is how vitamin D was obtained. Although vitamin D is in some animal foods it is in relatively low quantities and to my knowledge there are no known ancestral populations that thrived on oral vitamin D sources. Although we can absorb vitamin D orally because it is a fat soluble vitamin, there is strong emerging research that suggests this lacks many of the benefits of vitamin D.
The majority of the research documenting the benefits of optimized vitamin D levels was done with those that had not taken oral vitamin D but had increased their levels naturally through exposure to the sun. I personally have not taken any oral vitamin D for over two years and have been able to consistently keep my levels over 60 ng/ml. This is partly related to the fact that I work in a sub-tropical environment in the winter.
If I could not do that there is no question that I would still not use oral vitamin D but would use a high quality safe tanning bed that used electronic ballasts that did not emit any dangerous EMF.
Alternative to the Sun – A Safe Tanning Bed

During the summer months, you can generally get enough vitamin D from just spending some time outside every day. Under optimal environmental exposures your body can produce about 20,000 IU of vitamin D per day with full body exposure, about 5,000 IU with 50 percent of your body exposed, and as much as 1,000 IU with just 10 percent of your body exposed.
In the winter months however, and/or times of the year when insufficient amounts of UVB rays reach your location, you will most likely not get enough vitamin D. In that case, I recommend using a safe tanning bed, which is still better than oral vitamin D.
One of the caveats here is to make sure you're not being exposed to harmful EMF exposure. Most tanning equipment, and nearly all of the early beds from which these studies were conducted, use magnetic ballasts to generate light. These magnetic ballasts are well known sources of EMF fields that can contribute to cancer. If you hear a loud buzzing noise while in a tanning bed, it has a magnetic ballast system. I strongly recommend you avoid these types of beds and restrict your use of tanning beds to those that use electronic ballasts.



Dr. Mercola

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