June 2009 - Vol 4 Issue 6

Vitamin D Does it All
The many benefits of vitamin D
by Michelle Gibeault Traub, R.D.

It may be the closest thing to a miracle drug that nature has ever provided. Made from sunlight or consumed from food or supplements, vitamin D has the potential to boost immunity, improve mood, and even prevent diseases such as osteoporosis, cancer, diabetes, and MS. Talk about amazing! So why are so many of us deficient in this vital vitamin? Could some of our healthiest habits actually be the cause?

What is vitamin D?

Vitamin D is quite mysterious. Although it has been classified as a vitamin, a term that typically refers to a nutrient that must be obtained from the diet, this is a bit of a misnomer since D can actually be made by the skin in response to UVB rays. In addition, vitamin D serves as a hormone regulating calcium and phosphorus metabolism, along with other cell activities. Whether we think of it as a hormone or a vitamin, research in the past few years have made it clear that vitamin D is much more important than we ever realized.

What does vitamin D do?

Previously only known for its role in assisting calcium absorption and therefore contributing to strong bones and teeth, research in the past few years extends vitamin D’s benefits to virtually every part of the body. Some of the key areas where vitamin D appears to be important include:

• Immunity – exhibiting anti-viral activity that helps ward off illnesses such as flu and Tuberculosis and inhibiting inflammatory responses like those seen in asthma.
• Cell protection and gene expression - leading to decreased rates of cancer and autoimmune disorders.
• Balance and muscle strength – contributing to fall prevention and fewer broken bones (particularly in the elderly).
• Cardiovascular health – with optimal levels associated with lower rates of heart disease, stroke, and hypertension.
• Mental health – with rates of depression increasing with D deficiency. Some researchers also theorize that deficiency could lead to dementia.

Vitamin D deficiency – Who’s at risk?

Getting enough vitamin D through diet has been tricky since the main dietary sources tend to be fatty fish, which are not widely consumed in the daily diet. In addition, the healthy habit of shielding the skin from the harmful UV rays that are associated with skin cancer means making D from sun exposure is unlikely for most people. So, a reasonable response to “Who’s at risk for vitamin D deficiency?” is “you!” In fact a recent study estimated that nearly 90% of the adult population may have insufficient levels of D. Clearly everyone must take stock of their vitamin D intake, but the following groups are at particularly high risk for deficiency:

• Dark-skinned individuals whose pigmentation actually blocks D production.
• The elderly because their skin is unable to properly convert D to its active form.
• Breast-fed babies, since breast milk does not contain vitamin D.
• Individuals with digestive disorders that inhibit absorption such as Crohn’s Disease, Celiac Disease, Cystic Fibrosis, Liver Disease, or those who have had intestinal surgery.
• Anyone living above 42 degrees north latitude (extending across the US from Northern California to Boston) because the sun’s angle and intensity does not provide enough UVB rays for the skin to produce vitamin D from November through February.

While the risk for D deficiency is great, the only true way to know if you are deficient is through a blood test measuring the serum concentration of 25(OH)D. Levels less than 20-30 ng/mL indicate deficiency, with many physicians suggest that optimal levels fall in the range of 50-80 ng/mL.

Sunning safely

Although UV radiation is a known carcinogen contributing to melanomas that result in 8,000 deaths a year in this country, the benefit of vitamin D production may offset a bit of the risk. Luckily, very little direct sunlight is required to produce adequate amounts of the nutrient. Researchers estimate that when the skin on the face, arms, legs and back is exposed to summer sun in just 10 – 15 minutes 10,000 IUs of vitamin D can be produced. That amount is 25 times the current Daily Value (400 IU) for vitamin D. And, since the body is able to self-regulate the production, it is not possible to get too much vitamin D from sunlight. This leads some researchers to recommend sunlight as a more effective and safe means of increasing vitamin D levels. Still dermatologists remind us of the irreversible skin damage leading to premature aging and wrinkles that make daily or extended sun exposure a poor choice. In their opinions, supplementation or consuming ample fatty fish and fortified dairy products is the healthiest means of getting more D.

Whether you choose short sun baths or a diet complete with vitamin D-rich foods and supplements like Adora Calcium, the facts are clear you “D”efinitely need to “D”o more D.

Watch for next month’s “circle of health” where we discuss “The Great Vitamin D Debate” with updates on the latest recommendations and ways to increase your intake of vitamin D.

References

1. National Institutes of Health Office of Dietary Supplements. Dietary Supplement Fact Sheet: Vitamin D. retrieved 6/1/09 LINK
2. Melinda Beck. It’s D-Lightful: Vitamin D Gets Its Moment in the Sun. Wall Street Journal. July 15, 2008.
3. Tedd Mitchell, M.D. Asthma’s possible link to vitamin D. USA WEEKEND. May 29-31, 2009, p 9.
4. Stephen Daniells. D deficiency: Data denotes dementia danger? May 27, 2009 www.nutraingredients-usa.com. retrieved 6/1/09 LINK

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