Vitamin D supplement use and associated demographic, dietary and lifestyle factors in 8024 South Asians aged 40-69 years: Analysis of the UK Biobank cohort

Objective: Vitamin D deficiency (serum 25-hydroxyvitamin D<25 nmol/l) is extremely common in Western-dwelling South Asians but evidence regarding vitamin D supplement usage in this group is very limited. This work identifies demographic, dietary and lifestyle predictors associated with vitamin D supplement use. Design: Cross-sectional analysis of baseline vitamin D supplement use data. Setting: UK Biobank cohort. Subjects: In total, 8024 South Asians (Bangladeshi, Indian, Pakistani), aged 40-69 years. Results: Twenty-three per cent of men and 39 % of women (P<0·001) (22 % of Bangladeshis, 32 % of Indians, 25 % of Pakistanis (P<0·001)) took a vitamin-D-containing supplement. Median vitamin D intakes from diet were low at 1·0-3·0 μg/d, being highest in Bangladeshis and lowest in Indians (P<0·001). Logistic regression modelling showed that females had a higher odds of vitamin D supplement use than males (OR=2·02; 95 % CI 1·79, 2·28). A lower supplement usage was seen in younger persons (40-60 years v. >60 years: OR=0·75; 95 % CI 0·65, 0·86) and in those living outside Greater London (OR=0·53 to 0·77), with borderline trends for a lower BMI, higher oily fish intake and higher household income associated with increased odds of vitamin D supplement use. Conclusions: Vitamin D supplements were not used by most South Asians and intakes from diet alone are likely to be insufficient to maintain adequate vitamin D status. Public health strategies are now urgently required to promote the use of vitamin D supplements in these specific UK South Asian subgroups.