Estimation of the dietary requirement for vitamin D in free-living adults ≥64 y of age
| Autor: | Albert Flynn, S Muldowney, J. J. Strain, Emeir M. Duffy, Kevin D. Cashman, Anthony P. Fitzgerald, Julie M. W. Wallace, Maxine P. Bonham, Kelly M. Seamans, Alice J. Lucey, Nicola Taylor, Mairead Kiely, Geraldine Horigan, Tom R. Hill, Maria S. Barnes |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Sunlight
Vitamin medicine.medical_specialty Nutrition and Dietetics business.industry Dietary intake Medicine (miscellaneous) Vitamin D intake medicine.disease vitamin D deficiency Dietary Requirements chemistry.chemical_compound Endocrinology chemistry Younger adults Internal medicine medicine Vitamin D and neurology business |
| Zdroj: | The American Journal of Clinical Nutrition. 89:1366-1374 |
| ISSN: | 0002-9165 |
| DOI: | 10.3945/ajcn.2008.27334 |
| Popis: | Background: Older adults may be more prone to developing vitamin D deficiency than younger adults. Dietary requirements for vitamin D in older adults are based on limited evidence. Objective: The objective was to establish the dietary intake of vitamin D required to maintain serum 25-hydroxyvitamin D [25(OH)D] concentrations above various cutoffs between 25 and 80 nmol/L during wintertime, which accounted for the effect of summer sunshine exposure and diet. Design: A randomized, placebo-controlled, double-blind, 22-wk intervention was conducted in men and women aged >= 64 y (n = 225) at supplemental levels of 0, 5, 10, and 15 mu g vitamin D3/d from October 2007 to March 2008. Results: Clear dose-related increments (P 0.0001) in serum 25(OH)D were observed with increasing supplemental vitamin D-3 intakes. The slope of the relation between total vitamin D intake and serum 25(OH)D was 1.97 nmol . L-1 . mu g intake(-1). The vitamin D intake that maintained serum 25(OH)D concentrations >25 nmol/L in 97.5% of the sample was 8.6 mu g/d. Intakes were 7.9 and 11.4 mu g/d in those who reported a minimum of 15 min daily summer sunshine exposure or less, respectively. The intakes required to maintain serum 25(OH)D concentrations of >37.5, >50, and >80 nmol/L in 97.5% of the sample were 17.2, 24.7, and 38.7 mu g/d, respectively. Conclusion: To ensure that the vitamin D requirement is met by the vast majority (>97.5%) of adults aged >= 64 y during winter, between 7.9 and 42.8 mu g vitamin D/d is required, depending on summer sun exposure and the threshold of adequacy of 25(OH)D. This trial was registered at http://www.controlled-trials.com/ISRCTN20236112 as ISRCTN registration no. ISRCTN20236112. Am J Clin Nutr 2009;89:1366-74. |
| Databáze: | OpenAIRE |
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