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The Sunshine Vitamin
February 9, 2009
In 2008, vitamin D made headline after headline thanks to mounting research about its health benefits. A common thread among the key findings is that this vitamin is extremely important for many aspects of our health—and most of us aren't getting enough of it.
Why We Need D
There are numerous good reasons to supplement the diet with this key
vitamin. Here are just some of the benefits:
• This vitamin helps promote calcium absorption in the gut and is critical for bone growth and remodeling, according to the National Institutes of Health (NIH) (1). In fact, a lack of vitamin D can cause bones to become thin or brittle. But, taking adequate amounts of calcium and vitamin D can help prevent rickets in children and osteoporosis and osteomalacia in adults, says NIH (1). The U.S. Food and Drug Administration acknowledges the importance of vitamin D. In September 2008, the agency changed its labeling laws to note that there is a relationship between a reduced risk of osteoporosis and calcium and vitamin D (2).
• Some studies show that vitamin D levels may play a role in the prevention of colon, prostate, and breast cancers, says NIH (1).
• The Linus Pauling Institute suggests that vitamin D is key for immune health as a "potent immune system modulator." Its effects on the immune system may "enhance innate immunity and inhibit the development of autoimmunity" (3).
• A recent Johns Hopkins University study of 13,331 healthy men and women found that low vitamin D levels were associated with diabetes, smoking and a higher body mass index. And, low levels of this important vitamin were associated with a 26% increased rate of mortality from all causes (4). A separate study published in the Archives of Disease in Childhood indicated that having enough vitamin D in child-hood could ward off type 1 diabetes in adulthood. In fact, children given extra vitamin D were 30% less likely to develop the disease. This percentage increased as doses increased (5).
Are You Getting Enough?
Vitamin D is not found naturally in too many foods, so our bodies have
developed a method to synthesize it. When ultraviolet rays from the
sun comes in contact with our skin, we naturally produce vitamin D.
Fears of developing skin cancer have made individuals avoid sunlight
or slather on sun screens (which blocks the production of the vitamin
in our body). As a result, the best bets for getting enough vitamin
D are through high-quality dietary supplements, foods fortified with
the nutrient or certain fatty fish.
The exact amount of vitamin
D needed in healthy individuals is currently an issue of debate. The
last time the recommended daily allowance (RDA) for vitamin D was updated
was in 1997, which were mainly for bone disease prevention in children
and the elderly. Right now, guidelines suggest consuming 200 IU of vitamin
D everyday for healthy children and adults age 50 and younger; 400 IU
for healthy adults 51-70 years; and 600 IU for those 71 and older. However,
many researchers feel these amounts are far from sufficient, as studies
indicate that as many as half of Americans are vitamin D deficient (6).
Even more troubling are recent study findings that large numbers of
children and teens don't get enough vitamin D as even mild vitamin D
deficiency can lead to rickets, a bone disease. Nationwide Children's
Hospital recently found that 80% of 85 young patients at risk for osteoporosis
had insufficient levels of vitamin D in their blood. According to the
researchers (who published their findings in the journal, Pediatrics),
"Vitamin D insufficiency may contribute to low bone mass or even
make the underlying metabolic bone disease worsen if not treated. Vitamin
D is essential in bone growth and mineralization in children and adults"
(7).
In August 2008, the American Medical Association recommended that the U.S. government increase the RDI for vitamin D. Then in October of this year, the American Academy of Pediatrics suggested doubling vitamin D recommendations for infants, children and adolescents to 400 IU per day (8). Some experts have recommended as much as 1,000-2,000 IU or more of vitamin D daily. It remains to be seen whether the U.S. government will increase its official recommendations.
If you are concerned about whether you're getting enough vitamin D, talk to your healthcare provider about how much vitamin D you should take. Then, visit your local natural products store for recommendations on the right supplement brand for you. WF
References
1. National Institutes of Health, Office of Dietary Supplements, "Dietary
Supplement Fact Sheet: Vitamin D," http://ods.od.mh.gov/factsheets/vitamind.asp,
accessed November 23, 2008.
2. U.S. Food and Drug Administration, "Food Labeling: Health Claims;
Calcium and Osteoporosis, and Calcium, Vitamin D, and Osteoporosis.
Final Rule," Fed. Regist. 29; 73 (189), 56477-56487 (2008).
3. Linus Pauling Institute, Oregon State University, "Micronutrient
Information Center: Vitamin D," http://lpi.oregonstate.edu/infocenter/vitamins/vitaminD,
accessed November 23, 2008.
4. "Large Study Links Inadequate Vitamin D Levels and Death,"
WholeFoods Magazine 31 (10), 10 (2008).
5. C.S. Zipitis andA.K. Akobeng, "Vitamin D supplementation in
early childhood and risk of type 1 diabetes: a systematic review and
meta-analysis" Arch. Dis. Childhood, 93, 512-517 (2008).
6. "Current Vitamin D Questioned," WholeFoods
Magazine 31 (9), 8 (2008).
7. Nationwide Children's Hospital, "Vitamin D Insufficiency May
Be Present in Pediatric Patients with Low Bone Density," press
release June 5, 2008.
8. American Academy of Pediatrics, Prevention of Rickets and Vitamin
D Deficiency in Infants, Children, and Adolescents, (Elk Grove Village
IL, 2008).
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