Todays post comes from the Fall Issue of the Nutrition Close-Up, ENCs newsletter that provides information on current nutrition and research trends and upcoming presentations. The post was authored by Yanni Papanikolaou, Vice President of Nutrition & Commercialization at Nutritional Strategies Inc. Nutritional Strategies Inc. is a scientific consulting firm specializing in developing evidence-based communications, conducting nutrition research, and advising on regulatory affairs. Yanni can be reached at [email protected] and at 519.504.9252. Please visit enc-online.org to access the current and previous issues of the Nutrition Close-Up.
While widespread cases of rickets date back at least to 17th century England, the cause remained elusive until McCollum and colleagues discovered vitamin D in 1957 and established a cure.1 While vitamin D research stalled for many years following that critical discovery, new research in recent years has reignited scientific interest in vitamin D and health outcomes. Low levels of vitamin D are now associated with various chronic diseases, including cancer, diabetes, osteoporosis, and cardiovascular disease.2 And the 2010 Dietary Guidelines for Americans indicated that vitamin D intakes are low enough to be considered a nutrient of public health concern for all ages.3 Even with the prevalent use of dietary supplements, observational evidence stemming from the National Health and Nutrition Examination Survey (NHANES) has shown that a significant number of American adults and children do not achieve the estimated average requirements (EAR)4 set forth by the 2010 Institute of Medicine (IOM) Food and Nutrition Board.
Exposure to the sun can influence vitamin D levels, and a high risk of vitamin D insufficiency exists in northern latitudes, among them northern regions of the U.S. In fact, researchers in 2007 examined vitamin D status of pregnant women and their neonates in and around Pittsburgh, PA by race and season, where more than 90% of women used prenatal vitamins. At time of delivery, vitamin D deficiency occurred in 29.2% of African American women and 45.6% of their babies; while vitamin D insufficiency occurred in 54.1% of African American women and 46.8% of their babies. The study further showed that 5% of white women and 9.7% of their babies were vitamin D deficient; and that 42.1% of white women and 56.4% of their babies were vitamin D insufficient. The study confirmed that both groups of pregnant women residing in this northern U.S. region were at high risk of vitamin D insufficiency, even while more than nine in 10 complied with advice to consume prenatal vitamins.5 Similar findings have been reported in healthy young adults of diverse ancestry living in the Toronto area, situated about 60 miles north of the U.S. border, further demonstrating the impact of latitude on vitamin D status.6
A recent study using data from NHANES 2001-2008 examined usual intakes of vitamin D from food and dietary supplements in individuals aged four years and greater.7 The study indicated that vitamin D disparities exist and are influenced by several demographic and/or socioeconomic factors, including race/ethnicity, income, and weight status. Percentages of individuals who did not meet their individual estimated average requirement (EAR) targets for vitamin D were high among all races. Individuals considered to have high household income had higher vitamin D intakes and were more likely to meet their EAR targets from a combination of food and dietary supplements compared to low- and middle-income individuals. Normal-weight individuals had greater calcium and vitamin D consumption and were more likely to meet the EAR targets from a combination of food and dietary supplements compared to overweight and obese individuals. Further, researchers indicated that excessive intakes of vitamin D above the IOMs Upper Limit value were low among all studied populations and overnutrification was not widely present across the analyses.
Vitamin D can be sourced in the diet through consumption of fatty fish, fish oils, eggs, dairy products, and supplements. While fish represents an important source for vitamin D intake, fish consumption remains low in the U.S.,8 making eggs and dairy foods favorable dietary alternatives to help increase vitamin D consumption. As part of a healthy diet, eggs can provide a good source of vitamin D, such that one large egg (50g) contributes 41 IU vitamin D. Currently, eggs fall under the category of Protein Foods Group in USDAs MyPlate. Recommendations for the protein food group range from 2-ounce equivalents for children aged 2-3 years to 6.5-ounce equivalents for adolescent boys aged 14-18 years and adult men aged 19-30 years. One egg counts as a 1-ounce equivalent in the protein foods group. In addition, eggs are a nutrient-dense food and provide several key essential nutrients. At 70 kcal, one large egg contains 12% daily value (DV) for protein, 10% DV for vitamin D, 15% DV for riboflavin and 10% DV for phosphorus.9 In addition, eggs represent a food that collaborates well with other nutrient-dense food items. With that in mind, consider how the nutrition adds up when individuals choose egg-containing foods like low-fat cheese omelets and vegetable frittatas.
Based on peer-reviewed published findings, dietary guidance messaging may need to amplify recommendations to meet public health goals for vitamin D. Indeed, increased egg consumption may provide one realistic, practical, and economical approach for improved vitamin D consumption in several American sub-populations.
References
1. DeLuca HF. History of the discovery of vitamin D and its active metabolites. BoneKEy Reports. 2014;3: doi: 10.1038/bonekey.2013.213
2. Soares MJ. Calcium and vitamin D for chronic disease: A time for action. Eur J Clin Nutr. 2011;65:985 doi: 10.1038/ejcn.2011.112.
3. US. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2010. 7th Edition, Washington, DC: U.S. Government Printing Office, December 2010.
4. Fulgoni VL III, Keast DR, Bailey RL, Dwyer J: Foods, fortificants and dietary supplements: where do Americans get their nutrients? J Nutr. 2011;141:18471854.
5. Bodnar LM, Simhan HN, Powers RW et al. High prevalence of vitamin D insufficiency in black and white pregnant women residing in the northern United States and their neonates. J Nutr. 2007;137:447-452.
6. Gozdzik A, Barta JL, Hongyu W, et al. Low wintertime vitamin D levels in a sample of healthy young adults of diverse ancestry living in the Toronto area: Associations with vitamin D intake and skin pigmentation. BMC Public Health. 2008;8:336 doi:10.1186/1471-2458-8-336.
7. Wallace TC, Reider C, Fulgoni VL. Calcium and vitamin D disparities are related to gender, age, race, household income level, and weight classification but not vegetarian status in the United States: Analysis of the NHANES 2001-2008 data set. J Am Coll Nutr. 2013;32:321-330.
8. Papanikolaou Y, Brooks J, Reider C, et al. U.S adults are not meeting recommended levels for fish and omega-3 fatty acid intake: Results of an analysis using observational data from NHANEs 2003-2008. Nutr J. 2014. 13:31 doi:10.1186/1475-2891-13-31.
9. USDA National Nutrient Database for Standard Reference, Release 27, Software v.2.0b. The National Agricultural Library.
Key Messages
- Low levels of vitamin D are now associated with various chronic diseases, including cancer, diabetes, osteoporosis, and cardiovascular disease.
- Individuals considered to have high household income and normal-weight individuals are more likely to meet their vitamin D intake targets through a combination of food and dietary supplements compared to low- and middle-income individuals and overweight individuals, respectively.
- One large egg contributes 41 IU vitamin D, contains 10% daily value for vitamin D, and collaborates well with other nutrient-dense food items.