A new study published in BMJ Open highlights the variation in vitamin D status between different ethnic groups and by season and geographical region within the UK.
The cross-sectional analysis included 449,943 individuals from the UK Biobank aged 40-69 years with measured serum vitamin D status. Data on sex, age, ethnic background, vitamin D supplementation, smoking, drinking and socio-economic status were collected using a questionnaire.
Vitamin D deficiency was more common in Asian (53.7%) and Black (34.9%) individuals than in White individuals (12%). Vitamin D deficiency was more prevalent during winter (23.1%) and spring (20%) than during summer (4.5%) and autumn (7.6%). Scotland had the highest prevalence of vitamin D deficiency (23.5%), whereas the southern regions had the lowest prevalence (South West, 7.9%; South East, 8.2%).
Male sex, abnormal body mass index, non-white ethnicity, smoking and higher socio-economic deprivation were identified as risk factors for vitamin D deficiency or insufficiency. Increasing age, vitamin D supplementation and alcohol consumption were associated with a lower risk of vitamin D deficiency.
"These results provide some evidence supporting the Public Health England recommendation for taking vitamin D supplementation in winter and for people with black or Asian ethnic backgrounds," the authors concluded.