The report covers updated population status for folic acid, vitamin D, iron, and iodine.
The Centers for Disease Control and Prevention (CDC) has released its “Second National Report on Biochemical Indicators of Diet and Nutrition,” outlining deficiencies and favorable population intake of various vitamins and nutrients in the U.S. population.
The report, based on blood and urine samples collected from participants in the CDC’s National Health and Nutrition Examination Survey (NHANES), emphasizes newly available data from 2003-2006. The report covers includes “first-time data” for a new indicator of iron deficiency and 24 healthy and unhealthy fatty acids, altogether offering more than twice as many biochemical indicators as the CDC’s 2008 report.
Key findings from the newest edition include an observation that vitamin D deficiency is as high as 31% in non-Hispanic blacks and a finding that higher vitamin and nutrient deficiencies may be occurring in specific age, gender, and race/ethnicity groups.
The CDC is planning for further analysis of the nation’s nutrition status; in the meantime, here are highlights from the report:
The report found that the fortification of cereal-grain products with folic acid, which began in 1998, has had a sustained positive impact on blood folate levels. The report shows folate deficiency dropped to less than 1 percent after fortification. The report also shows that blood folate levels in all race/ethnic groups are 50 percent higher since fortification began.
Before fortification began, approximately 12 percent of women of childbearing age were deficient in folate, as determined by blood folate levels. Folate is essential during periods when cells rapidly divide and grow, which is particularly important for women prior to and during pregnancy and for children during infancy. Folic acid can help prevent some major birth defects of the baby’s brain and spine, such as spina bifida.
The report found the highest rates of vitamin D deficiency in non-Hispanic blacks (31 percent) despite clinical data showing greater bone density and fewer fractures in this group. Further research is needed to explain why non-Hispanic blacks have better bone health but yet have a higher rate of vitamin D deficiency. According to the report, the vitamin D deficiency rate for Mexican-Americans was 12 percent and for non-Hispanic whites it was 3 percent.
Vitamin D is essential for good bone health but it may also improve muscle strength and protect against cancer and type 2 diabetes. Researchers are investigating these potential benefits, as well as, the vitamin D requirements for various groups.
Findings were not as encouraging with regard to the iodine status in young women (20-39 years of age). 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 indicates higher rates of iron deficiency in Mexican-American children aged 1 to 5 years (11 percent) and in non-Hispanic black (16 percent) and Mexican-American women (13 percent) of childbearing age (12 to 49 years) when compared to 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.
The report provides first-time data on blood levels of fatty acids in the U.S. population. These include heart healthy polyunsaturated fatty acids as well as saturated fatty acids that increase risk of heart disease. The report found heart healthy polyunsaturated fatty acid levels in plasma differ by race/ethnicity. 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.
CDC’s report is a detailed biochemical assessment of the nutrition status of the U.S. population. It is the second in a series of publications that provide an ongoing assessment of the U.S. population’s nutrition status. The series of reports provide information specific to population groups defined by age, gender, and race/ethnicity to show how these factors affect nutrition status in the United States.
CDC plans further analysis of report data that will help identify the influence of socio-economic and lifestyle factors on levels of nutrients in blood and urine. The agency also plans to continue its assessment of the nation’s nutrition status in future reports.
For more information on the nutrition report, visit http://www.cdc.gov/nutritionreport/.
For information on CDC’s National Biomonitoring Program, visit http://www.cdc.gov/nceh/dls/nbp.html.