Principal Investigator: Balz Frei, PhD
Co-investigators: Gerd Bobe, PhD, MPH and Simone Frei, MPH, MA
896 elementary school children from Franklin School, Wilson Elementary School, and Hoover Elementary School in Corvallis, Oregon, are invited to participate in this study.
Background
The results of several surveys indicate that many children don't obtain an adequate intake of many key micronutrients. The National Health and Nutrition Examination Survey (NHANES) and many other epidemiological studies have shown that a large number of Americans, including children, have inadequate dietary intakes of many vitamins and minerals essential to normal metabolism, good health, and disease prevention. Findings from the Multivitamins & Public Health Workshop convened in 2003 suggest that "multivitamin/mineral supplementation to increase micronutrient intake to recommended levels is a prudent, inexpensive, and convenient way to improve the public's health status."
In addition, there is increasing evidence of widespread, severe vitamin D deficiency in the US population, particularly in children. While parents and pediatricians may have assumed that children are getting enough vitamin D from sunshine exposure, vitamin D-rich foods, and vitamin D-fortified milk, a study published in 2009 found that 7 out of 10 children in the U.S. have inadequate vitamin D levels and nearly 1 in 10 (7.6 million) is deficient. Most people living above 40 degrees latitude do not obtain enough vitamin D from about mid-November to early March. People with dark-colored skin have a significantly lower ability to synthesize vitamin D from sunlight, as do the elderly; and obesity increases the risk of vitamin D deficiency because these individuals cannot easily access the vitamin D stored in their body fat.
Emerging scientific evidence shows that vitamin D deficiency or inadequacy not only causes rickets (weak and deformed bones), osteoporosis (breakable bones), and muscle pain and weakness, but also is associated with cancers of the breast, prostate, and colon, high blood pressure and heart disease, multiple sclerosis, rheumatoid arthritis and osteoarthritis, type 1 and 2 diabetes, irritable bowel syndrome, and Crohn's disease. In addition, research done in the Linus Pauling Institute by Dr. Adrian Gombart, Associate Professor of Biochemistry and Biophysics, has shown that vitamin D plays a critical role in immune function by enhancing the production of a protein in the body that can fight viruses and bacteria. Hence, vitamin D plays an important role in preventing upper respiratory tract infections, tuberculosis, and other viral and bacterial infections.
Based on these findings, the Linus Pauling Institute currently recommends that children supplement their diet with a daily children's multivitamin/mineral and aim for a daily intake of 600 to 1000 IU of vitamin D from their diet and supplements to meet recommended intake levels and achieve good health.
Project DescriptionThe objectives of this study are to i) assess the dietary intake levels of all vitamins and essential minerals in a cohort of elementary school children and ii) assess the children's vitamin D body status. Most vitamin D (cholecalciferol) in the body is synthesized in the skin upon exposure to ultraviolet B (UVB) radiation from sunlight, and only a limited amount is obtained from the diet, such as fish or vitamin D-fortified milk or orange juice. Therefore, assessment of dietary intake of vitamin D—unlike all other vitamins—does not provide an accurate evaluation of a person's vitamin D status. To assess the latter, blood levels of vitamin D need to be measured. There is good scientific consensus that serum vitamin D levels below 32 ng/mL indicate insufficiency.
A validated dietary questionnaire (Block Kids Food Questionnaire) and a vitamin D test kit will be sent to the enrolled students’ homes. Both—the questionnaire and the vitamin D test—need to be completed at home. The vitamin D test kit, provided by ZRT Laboratory (Beaverton, OR), involves a nick on one finger to collect a few spots of blood and needs to be done once in the morning before eating or drinking.
Results of this project will identify specific vitamins and essential minerals that are not obtained by study participants in recommended amounts from their diet (estimated average requirement [EAR], adequate intake [AI], and/or recommended dietary allowance [RDA]) or not present in the body in adequate amounts (vitamin D). The results of the dietary questionnaire will be compared with the results of the same questionnaire administered to the 3rd through 5th grade students who participated in the LPI Fitness & Nutrition Study at Adams School in Corvallis, OR.
The results of this study may be published and lead to new recommendations for dietary supplementation of children with specific vitamins and minerals to meet recommended intake levels and achieve good health.
SponsorThis study is funded in full by USANA Health Sciences, Inc., Salt Lake City, UT.
