As many as two-thirds of obese African-American women may have vitamin D deficiency, according to research presented at the annual meeting of the Endocrine Society.

Dr. Shamik Parikh of the National Institute of Child Health and Human Development reported on a study in which vitamin D levels in 59 overweight African-American women were compared to those in 95 Caucasian women.

He said 66 percent of the obese African-Americans had low vitamin D levels compared to 5 percent of the white women.

Almost half of the black women (48 percent) also had secondary hyperparathyroidism -- a condition that occurs when the body produces extra parathyroid hormone because calcium levels are too low. This occurs when vitamin D levels are low.

"We already know that dark skin pigment and increased body weight put people at higher risk for developing vitamin D deficiency," said Parikh. "Our findings suggest that obese African Americans, especially women, should be screened regularly for vitamin D deficiency. They may benefit from dietary modification, including vitamin D supplements."

Other sources: National Institute of Child Health and Human Development