(HealthDay) -- Most people in the United States are getting adequate nutrition, but some groups experience lower levels of vital nutrients than that which is recommended for good health, according to the Second National Report on Biochemical Indicators of Diet and Nutrition released April 2 by the U.S. Centers for Disease Control and Prevention.
To assess nutritional trends and update the first report, which covered the years 1999 to 2002, researchers from the CDC analyzed blood and urine concentrations for 58 diet and nutrition biochemical indicators from a representative sample of the U.S. population during the years 2003 to 2008.
The researchers found that most people in the United States had good levels of vitamin D and A; however, vitamin D levels were found to be inadequate in some groups, most notably in non-Hispanic blacks, 31 percent of whom were deficient in vitamin D. In addition, Mexican-American children aged 1 to 5 and Mexican-American and non-Hispanic black women of childbearing age had higher rates of iron deficiency than other racial or ethnic groups; blood folate levels in all race/ethnic groups were up 50 percent since the fortification of cereal-grain products with folic acid began; and women of child-bearing age were found to have iodine levels that were just above iodine insufficiency.
"These findings are a snapshot of our nation's overall nutrition status," Christopher Portier, Ph.D., director of the CDC's National Center for Environmental Health, said in a statement. "Measurements of blood and urine levels of these nutrients are critical because they show us whether the sum of nutrient intakes from foods and vitamin supplements is too low, too high, or sufficient."