Effect of adiposity on vitamin D status and the 25-hydroxycholecalciferol response to supplementation in healthy young and older Irish adults

• Published in: British journal of nutrition Vol. 107; no. 1; pp. 126 - 134
• Main Authors: Kirsty Forsythe, L., Livingstone, M. Barbara E., Barnes, Maria S., Horigan, Geraldine, McSorley, Emeir M., Bonham, Maxine P., Magee, Pamela J., Hill, Tom R., Lucey, Alice J., Cashman, Kevin D., Kiely, Mairead, Strain, J. J., Wallace, Julie M. W.
• Format: Journal Article
• Language: English
• Published: Cambridge Cambridge University Press 14.01.2012
• Subjects: 25-hydroxycholecalciferol; Adipose Tissue - growth & development; Adiposity; Adult; Age Factors; Aged; Biological and medical sciences; blood serum; Body Mass Index; Body Size; Calcifediol - blood; cholecalciferol; Cholecalciferol - administration & dosage; compliance; Cross-Sectional Studies; Dietary Supplements; elderly; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Health; Humans; Ireland - epidemiology; latitude; lean body mass; Male; Middle Aged; Nutritional Status; obesity; Older people; Patient Compliance; Seasons; skinfold thickness; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin D; Vitamin D Deficiency - epidemiology; Vitamin D Deficiency - prevention & control; vitamin status; waist circumference; winter; Young Adult; Young adults; Ireland; Human; Vertebrata; Mammalia; Adiposity; Vitamin D; Young adult; Healthy adults; 25-Hydroxycholecalciferol; Vitamin D status; Supplementation; BMI
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114511002662

There is increasing epidemiological evidence linking sub-optimal vitamin D status with overweight and obesity. Although increasing BMI and adiposity have also been negatively associated with the change in vitamin D status following supplementation, results have been equivocal. The aim of this randomised, placebo-controlled study was to investigate the associations between anthropometric measures of adiposity and the wintertime serum 25-hydroxycholecalciferol (25(OH)D) response to 15 μg cholecalciferol per d in healthy young and older Irish adults. A total of 110 young adults (20–40 years) and 102 older adults ( ≥ 64 years) completed the 22-week intervention with >85 % compliance. The change in 25(OH)D from baseline was calculated. Anthropometric measures of adiposity taken at baseline included height, weight and waist circumference (WC), along with skinfold thickness measurements to estimate fat mass (FM). FM was subsequently expressed as FM (kg), FM (%), FM index (FMI (FM kg/height m 2 )) and as a percentage ratio to fat-free mass (FFM). In older adults, vitamin D status was inversely associated with BMI (kg/m 2 ), WC (cm), FM (kg and %), FMI (kg/m 2 ) and FM:FFM (%) at baseline ( r − 0·33, − 0·36, − 0·33, − 0·30, − 0·33 and − 0·27, respectively, all P values < 0·01). BMI in older adults was also negatively associated with the change in 25(OH)D following supplementation (β − 1·27, CI − 2·37, − 0·16, P  = 0·026); however, no such associations were apparent in younger adults. Results suggest that adiposity may need to be taken into account when determining an adequate wintertime dietary vitamin D intake for healthy older adults residing at higher latitudes.