CDC report: Some ethnic groups need to boost vitamin D, iron supplementation


ATLANTA — Overall, the U.S. population has good levels of vitamin A and folate in the body, but some groups still need to increase their levels of vitamin D and iron, according to the "Second National Report on Biochemical Indicators of Diet and Nutrition," released Monday by the Centers for Disease Control and Prevention.

"These findings are a snapshot of our nation's overall nutrition status," said Christopher Portier, director of CDC's National Center for Environmental Health. "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."

The report found the highest rates of vitamin D deficiency in non-Hispanic African-Americans (31%) despite clinical data showing greater bone density and fewer fractures in this group. Further research is needed to explain why non-Hispanic African-Americans have better bone health yet have a higher rate of vitamin D deficiency. According to the report, the vitamin D deficiency rate for Mexican-Americans was 12%, while for non-Hispanic whites, it was 3%.


Findings were not as encouraging with regard to the iodine status in young women (ages 20 to 39 years). This age group had iodine levels that were just above iodine insufficiency. The young women also had the lowest iodine levels among any age group of women. Iodine is an essential component of thyroid hormones that regulate human growth and development. Iodine deficiency disorders include mental retardation, hypothyroidism, goiter, cretinism and varying degrees of other growth and developmental abnormalities. Iodine is especially important in women during childbearing years to ensure the best possible brain development of the fetus during pregnancy.

Using a new marker of iron status, the report indicated higher rates of iron deficiency in Mexican-American children ages 1 to 5 years (11%) and in non-Hispanic African-Americans (16%) and Mexican-American women (13%) of childbearing age (ages 12 to 49 years) when compared with other race/ethnic groups. The new iron marker measurements will help clinicians better interpret iron status in individuals, especially in persons with chronic disease that includes inflammation, such as certain cancers.


"Research shows that good nutrition can help lower people's risk for many chronic diseases. For most nutrients, the low deficiency rates, less than 1% to 10%, are encouraging, but higher deficiency rates in certain age and race/ethnic groups are a concern and need additional attention," said Christine Pfeiffer, lead researcher in the Division of Laboratory Sciences in CDC's National Center for Environmental Health.

CDC's "Second Nutrition Report" established blood and urine reference levels for 58 biochemical indicators; more than twice as many indicators as its first report, published in 2008. The report included first-time data for a new indicator of iron deficiency and for 24 healthy and unhealthy fatty acids.

The report provided first-time data on blood levels of fatty acids in the U.S. population, including both heart healthy polyunsaturated fatty acids as well as saturated fatty acids that increase risk of heart disease. These first time measurements provide a baseline that will allow CDC to track fatty acid levels over time, which will evaluate our nation's progress toward heart healthy diets.

For the full nutrition report, click here.

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