Tag Archives: Vitamin D

Hypovitaminosis D and Body Fat

by Chantal Charo Ph.D.   Vitamin D or the “sunshine vitamin” has seen a lot of popularity lately thanks to discoveries about deficiencies in the general population. Shocking data from the National Health and Nutrition Examination Survey (NHANES) demonstrate that more than 90% of the non Caucasian population and 75% of the Caucasian population of the United States suffer from vitamin D insufficiency. What exactly does Vitamin D do?

Vitamin D plays a role in bone metabolism and calcium homeostasis and many researchers have shown the benefits of vitamin D supplementation in preventing bone loss and muscle injury in older women. However, in recent years it has become clear that the health risks associated with low levels of Vitamin D go beyond age related diseases. Hypovitaminosis D is linked to an increased risk of osteoporosis, diabetes, cardiovascular diseases, and cancer.  Much of the growing interest in vitamin D was caused by its association with obesity, a known risk factor for the chronic conditions described. A study published in the journal Nutritional Research showed that excessive administration of vitamin D lead to a significant decrease in body fat of rats. In this study, researchers separated rats into two groups: one overfed mostly with calories from fat, and the other group overfed with a sugar rich diet. Each of these groups was split in half, with one half receiving a “sub-optimal” dose of Vitamin D and the other receiving 10,000 IE of Vitamin D, and a slightly higher amount of calcium than what the other group received. The results of this study were surprising; researchers found that even though the rats were overfed, administering large dose of Vitamin D and calcium resulted in weight loss and hypertrophy compared to the group that received the sub optimal doses of Vitamin D.  Data from this study demonstrated a correlation of high doses of Vitamin D and protein synthesis. They claim that the rats receiving the high Vitamin D and calcium doses manufactured more of a protein that helps muscles burn fat for energy which lead to the decrease in body fat and increase in musculature. However, this study was clearly done in rats, not in humans. Nevertheless, similar results were obtained from studies done in humans. it is now well established that low vitamin D status, may increase body fat and that increasing Vitamin D levels may inhibit adipogenesis . And, reciprocally, a modest weight loss of 10% could increase the levels Vitamin D according to Holecki M.’s group. It has even been suggested that Vitamin D supplementation contributes to both upper and lower body muscle strength and could be used to preserve age related muscle loss. Muscle cells contain vitamin D receptor and several studies have demonstrated that serum levels of Vitamin D correlate with improved physical performance. On the other hand, people with insufficient or deficient levels of Vitamin D are likely to have fatty muscles because of an increase in fat infiltration. Obviously, this information is valuable for everyone not only for both dieters and fitness enthusiasts- who wouldn’t want to lose fat and gain some definition? All it takes, according to these studies, is a adding a couple of Vitamin D/Calcium pills to your diet. However, should you supplement your diet with Vitamin D? Vitamin D is synthesized when the skin is exposed to UV from the sun, or it is obtained from food, especially fatty fish. Moderately increasing Vitamin D by diet or sun exposure is harmless. Although rare, excess Vitamin D can cause toxicity by causing hypercalcemia, or an increase of calcium build up in the blood, kidney problems and death. Toxic doses for Vitamin D are not yet established, however, reports show that a dose of 50 000 IU or greater for several months can cause Hypervitaminosis D related toxicity. The RDA of Vitamin D is 600 IU/day. As always, talk to your doctor before taking vitamin and mineral supplements.


Dr. Chantal Charo  is an assistant professor of virology and immunology and a licensed sports nutritionist from Miami, FL.  She is an interdisciplinary biomedical researcher with a particular focus on women’s health. Her research studies and teaching interests include insulin resistance, the biological pathways by which IGF-1 affects gynecological cancers, Vitamin D, the metabolic syndrome, PCOS, female athlete triad syndrome, microRNAs, breast and ovarian cancer. Dr. Charo is also involved in many clinical trial, including a Phase I trial for metastatic ovarian cancer. Chantal earned her Ph.Ds. in Biomedical Sciences and Cancer Biology from the University of Texas Houston and the UT MD Anderson Cancer Center; and she holds an M.Sc in Biomedical Sciences and a B.S. in biology with a minor in chemistry. As sports nutritionist trained with a leading supplement company, Dr. Charo investigated the effects of carbohydrate intake and hormonal balance in women, as well as the Euthyroid Sick syndrome and the female athlete. Chantal hosts a medical segment on a local daily talk show which aims at promoting awareness to women and combating health illiteracy. In support of her research, Chantal has received fellowships from National Cancer Institute, the National Institute of Health and more. She is a Fellow of the American Association of Cancer Researchers, the American Pancreatic Association and the American Breast Cancer Association, and was the recipient for many outstanding scientist awards.



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Sunshine On My Shoulders Makes Me :)

By: Jose Antonio, PhD

Date Published: April 2011.

Sunshine On My Shoulders- John Denver (YouTube video)

Sunshine on my shoulders makes me happy.

Sunshine in my eyes can make me cry.

Sunshine on the water looks so lovely.

Sunshine almost always makes me high.

–          Lyrics by John Denver –


I’m not sure it makes me high, but damn it sure makes you feel good.  And part of the reason we need sun exposure is so that our bodies can make vitamin D (aka the ‘sun vitamin’).  For you old school music buffs, John Denver’s hit song from way back in the Jurassic period truly is prophetic with regards to the value of sun exposure.

Some scientists now believe vitamin D is the pre-eminent vitamin.  It does so many good things that to not supplement it would be akin to not taking a parachute when you go sky diving.  Not smart, eh.  We know for example that vitamin D deficiency is an increasingly described phenomenon worldwide, with dramatic effects on calcium metabolism and bone health. Vitamin D deficiencies have also been associated with a variety of not so good things. Things that make you want to curl up into a ball, pig out on donuts, and watch TiVo’d reruns of the Sopranos.  For instance, you might have a greater risk of bowel and colonic cancer, arthritis, diabetes and heart disease.

In recent decades, there has been increased awareness of the impact of vitamin D on muscle morphology and function; In the early part of 20th century, athletes and coaches felt that ultraviolet rays had a positive impact on athletic performance, and abracadabra, that’s why we love the sun. Well sort of.  The bikinis help too.

“Both cross-sectional and longitudinal studies allude to a functional role for vitamin D in muscle and more recently the discovery of the vitamin D receptor in muscle tissue provides a mechanistic understanding of the function of vitamin D within muscle.”(1)

Also, vitamin D supplementation has been shown to improve tests of muscle performance, reduce falls, and possibly impact on muscle fiber composition and morphology in vitamin D deficient older adults.(2)  Another study found that vitamin D was significantly associated with muscle power and force in adolescent girls.(3)

The bottom line is this: the RDA for vitamin D is paltry (200-600IUs daily); that would be like walking across the Sahara desert with bottle of Jack Daniels and expecting it to hydrate you for the long march.  Instead, get out in the sun! Expose your body at least 3 times per week to 30 minutes of good UV light.  And if you live in a cruddy place like Cleveland or Seattle where there are about as many sunny days as there are hairs on a bald man’s head, then supplement my friend.  Take at least 2000-4000IUs per day.


About the Author:

Jose_Antonio_head_shot_2Jose Antonio is an author, speaker, radio show host, sports nutrition scientist, and avid outrigger paddler.  www.theissn.org






1. Hamilton B. Vitamin D and Human Skeletal Muscle. Scand J Med Sci Sports 2009.

2. Ceglia L. Vitamin D and its role in skeletal muscle. Curr Opin Clin Nutr Metab Care 2009;12:628-33.

3. Ward KA, Das G, Berry JL, et al. Vitamin D status and muscle function in post-menarchal adolescent girls. J Clin Endocrinol Metab 2009;94:559-63.