Serum 25-hydroxyvitamin D concentration and its determinants in the very old: the Newcastle 85+ Study. Issue 3 (March 2016)

• Record Type: Journal Article
• Authors: Hill, T.; Granic, A.; Davies, K.; Collerton, J.; Martin-Ruiz, C.; Siervo, M.; Mathers, J.; Adamson, A.; Francis, R.; Pearce, S.; Razvi, S.; Kirkwood, T.; Jagger, C.
• Is Part Of: Osteoporosis international. Volume 27:Issue 3(2016)
• Page Start: 1199
• Page End: 1208
• Publication Date: 2016-03
• Subjects: Aged 80 and over -- Determinants -- Newcastle 85+ cohort study -- Serum 25-hydroxyvitamin D; Osteoporosis -- Periodicals; Bones -- Metabolism -- Disorders -- Periodicals; 616.716005
• DOI: 10.1007/s00198-015-3366-9
• Languages: English
• ISSNs: 0937-941X

Abstract

Abstract Summary Data on vitamin D status in very old adults are lacking. The aim of this study was to assess 25-hydroxyvitamin D [25(OH)D] concentrations and its predictors in 775 adults aged 85 years old living in North-East England. Low 25(OH)D was alarmingly high during winter/spring months, but its biological significance is unknown. Introduction Despite recent concerns about the high prevalence of vitamin D deficiency in much of the British adult and paediatric population, there is a dearth of data on vitamin D status and its predictors in very old adults. The objective of the present study was to describe vitamin D status and its associated factors in a broadly representative sample of very old men and women aged 85 years living in the North East of England (55° N). Methods Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were analysed in 775 participants in the baseline phase of the Newcastle 85+ cohort study. Season of blood sampling, dietary, health, lifestyle and anthropometric data were collected and included as potential predictors of vitamin D status in ordinal regression models. Results Median serum 25(OH)D concentrations were 27, 45, 43 and 33 nmol/L during spring, summer, autumn and winter, respectively. The prevalence of vitamin D deficiency according to North American Institute of Medicine guidelines [serum 25(OH)D <30 nmol/L] varied significantly with season with the highest prevalence observed in spring (51 %) and the lowest prevalence observed in autumn (23 %;P < 0.001). Reported median (inter-quartile range) dietary intakes of vitamin D were very low at 2.9 (1.2–3.3) μg/day. In multivariate ordinal regression models, non-users of either prescribed or non-prescribed vitamin D preparations and winter and spring blood sampling were associated with lower 25(OH)D concentrations. Dietary vitamin D intake, disability score and disease count were not independently associated with vitamin D status in the cohort. Conclusion There is an alarming high prevalence of vitamin D deficiency (<30 nmol/L) in 85-year-olds living in North East England at all times of the year but particularly during winter and spring. Use of vitamin D containing preparations (both supplements and medications) appeared to be the strongest predictor of 25(OH)D concentrations in these very old adults.