BACKGROUND: Inadequate vitamin D status is common in many populations around the world. OBJECTIVE: The aim was to evaluate potentially modifiable determinants of vitamin D status in an older population. DESIGN: This was a cross-sectional study from a population-based cohort including 538 white Dutch men and women aged 60-87 y. Vitamin D status was assessed by plasma 25-hydroxyvitamin D [25(OH)D] concentrations. RESULTS: In the winter period, 51% of the subjects had 25(OH)D concentrations <50.0 nmol/L. Greater body fatness and less time spent on outdoor physical activity were associated with worse vitamin D status. Regular use of vitamin D-fortified margarine products [odds ratio (OR) in a comparison of intake of >or=20 g/d with none: 0.41; 95% CI: 0.20, 0.86; P for trend < 0.001], fatty fish (OR for servings of >or=2/mo versus none: 0.41; 95% CI: 0.16, 1.04; P for trend = 0.01), and vitamin D-containing supplements (OR for >or= 1/d versus none: 0.33; 95% CI: 0.17, 0.63; P for trend < 0.001) were inversely associated with vitamin D inadequacy [25(OH)D <50.0 nmol/L]. We estimated that combined use of margarine products (20 g/d), fatty fish (100 g/wk), and vitamin D supplements (>or=1/d) was associated with a 16.8 nmol/L higher 25(OH)D concentration than was the use of none of these. However, none of the participants reached these intakes for all 3 factors. CONCLUSION: Because few foods are vitamin D-fortified and the amounts of vitamin D in supplements are low, it is difficult to achieve adequate vitamin D status through increasing intakes in the Netherlands and in countries with similar policies.
van Dam, R. M., Snijder, M. B., Dekker, J. M., Stehouwer, C. D., Bouter, L. M., Heine, R. J., & Lips, P. (2007). Potentially modifiable determinants of vitamin D status in an older population in the Netherlands: the Hoorn Study. American Journal of Clinical Nutrition, 85(3), 755-761. https://doi.org/10.1093/ajcn/85.3.755