Many in U.S. get too little vitamin D

April 13, 2011

New figures from the National Center for Health Statistics show that while nearly two-thirds of the U.S. population has sufficient vitamin D levels, about one-fourth are bordering on vitamin D inadequacy and 8 percent on vitamin D deficiency, HealthDay News reports.

Hyattsville, Md. - New figures from the National Center for Health Statistics show that while nearly two-thirds of the U.S. population has sufficient vitamin D levels, about one-fourth are bordering on vitamin D inadequacy and 8 percent on vitamin D deficiency, HealthDay News reports.

At the other extreme, 1 percent of Americans have vitamin D levels so high they could be harmful.

Researchers analyzed National Health and Nutrition Examination Survey data from 2001 to 2006 for people age 1 and older. The analysis showed that the risk for vitamin D deficiency differed by age, sex and race or ethnicity. Findings include:

• By age, the risk for deficiency ranged from 1 to 8 percent among males and 1 to 12 percent among females. For both sexes, the risk was lowest among children ages 1 to 8 and increased significantly until age 30 in men and 18 in women. After that, risk changed little.
• Whites were less likely than blacks or Mexican-Americans to be at risk for vitamin D deficiency.
• Among women of childbearing age, those who were pregnant or lactating were less likely to be at risk for vitamin D deficiency than women who were neither.
• Though vitamin D deficiency became more common in the United States in 1988-1994 and 2001-2002, risk for the deficiency did not change between 2001-2002 and 2005-2006.
• About 4 percent of males age 12 and older had vitamin D levels that put them at risk for deficiency in 1988-1994, and 17 percent were at risk for inadequacy. Those numbers rose to 7 percent and 22 percent, respectively, by 2001-2002.
• Among females age 12 and older, vitamin D deficiency rose from 7 percent in 1988-1994 to 11 percent in 2001-2002. However, the proportion of females with inadequate levels of vitamin D dropped from 30 percent to 25 percent in that time.

The National Institute of Medicine defines sufficient vitamin D as a serum 25-hydroxyvitamin D value of 50-125 nmol/L. A value of 30-49 nmol/L is defined as inadequate and less than 30 nmol/L is considered deficient.