African-American, Caucasian women should take identical vitamin D doses

African-American women battling vitamin D deficiencies need the same dose as Caucasian women to treat the condition, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

Although with darker skin tones tend to have lower levels of the biomarker used to measure levels, called 25-hydroxyvitamin D or 25OHD, the study found that older African-American and Caucasian women responded in the same way when they received vitamin D supplements.

Unlike many vitamins that are absorbed primarily from foods, the body's main source of vitamin D is sunlight. Vitamin D deficiency, which is primarily caused by inadequate exposure to sunlight and very poor diet, can result in abnormalities in calcium, phosphorus and bone metabolism. Vitamin D deficiency can cause rickets in children or a bone-softening condition called osteomalacia and muscle weakness in adults.

In a double-blind study that gave varying vitamin D doses to African-American and of similar body size, levels of the 25OHD biomarker were very similar. The findings suggest that vitamin D absorption and metabolism is the same in both groups. Researchers concluded that African-American women tend to have lower levels of the biomarker 25OHD because they naturally produce less vitamin D in the skin after sunlight exposure.

"African-American women don't have to worry about taking larger doses of vitamin D to compensate," said J. Chris Gallagher, MD, of Creighton University School of Medicine in Omaha, Neb., and lead author of the study. "They should follow the current medical guidelines for vitamin D supplementation suggested recently by the Institute of Medicine."

The Endocrine Society has issued a separate set of clinical practice guidelines governing vitamin D dosage.

Previously there was no research in minority populations to determine whether the same guidelines applied to them. Researchers designed this study to develop dosing guidelines for older African-American women. The study, which looked at vitamin D doses in 110 African-American women between the ages of 57 and 90, was the first randomized controlled dose response study conducted in this population.

"We saw a real need to study optimal vitamin D doses in African-American women and help their health care professionals make informed medical decisions," Gallagher said.

Although exposure to sunlight increases vitamin D levels, concerns about melanoma and other types of skin cancer necessitate avoidance of excessive exposure to the sun.

More information: The guidelines are available at www.endo-society.org/guideline… amin-D-Guideline.pdf.

add to favorites email to friend print save as pdf

Related Stories

Vitamin D levels lower in African-Americans

Oct 02, 2010

African-American women had lower vitamin D levels than white women, and vitamin D deficiency was associated with a greater likelihood for aggressive breast cancer, according to data presented at the Third AACR Conference ...

One size doesn't fit all for vitamin D and men

Sep 20, 2011

African-American men living in areas with low sunlight are up to 3 ½ times more likely to have Vitamin D deficiency than Caucasian men and should take high levels of Vitamin D supplements, according to a new study from ...

Recommended for you

Harm from baseball concussions may linger, study finds

27 minutes ago

(HealthDay)—Even after they're cleared to play following a concussion, baseball players' batting skills are worse than normal, which suggests they may not be fully recovered, a new study suggests.

Don't let high altitude ruin your holiday trip

3 hours ago

(HealthDay)—When you're planning your holiday get-away, don't forget to factor high altitude into your vacation sports—such as skiing or hiking, a sports medicine specialist cautions.

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.