Vitamin D status and cardiometabolic risk factors in young adults in Hong Kong: associations and implications.

BACKGROUND AND OBJECTIVES: Vitamin D deficiency is reportedly common, but we lack data from young adults. Such data are of interest because epidemiological data support vitamin D as a possible risk modulator for diabetes and cardiovascular ('cardiometabolic') disease. Our objectives were to assess vitamin D status (as plasma 25(OH)D concentration) and investigate associations between this and biomarkers of cardiometabolic disease risk in a group of still-healthy young adults in Hong Kong.

METHODS AND STUDY DESIGN: In this observational study, fasting venous blood was collected from 196 (63 males, 133 females), young (18-26 years) non-smoking, nonobese, consenting adults in good general health. Plasma 25(OH)D was measured by LC-MS/MS. A panel of established cardiometabolic risk factors (HbA1c, plasma glucose, lipid profile, hsCRP) and blood pressure were also measured.

RESULTS: Mean (SD) plasma 25(OH)D concentration was 42.1 (13.0), with range 15.7-86.8 nmol/L; 141/196 subjects (72%) had vitamin D deficiency (25(OH)D <50 nmol/L); 13/184 (6.6%) were severely deficient (<25 nmol/L). Inverse association was seen between 25(OH)D and fasting glucose (r=-0.18; p<0.05). Higher HbA1c and TC:HDL-C ratio and lower HDL-C were seen in those with plasma 25(OH)D <25 nmol/L (p<0.05).

CONCLUSIONS: Vitamin D deficiency was highly prevalent and associated with poorer cardiometabolic risk profile in these young adults. Public health strategies for addressing vitamin D deficiency are needed urgently. These new data provide support for further study on vitamin D deficiency as a modifiable risk factor for cardiometabolic disease and the ameliorative effects of increased vitamin D intake on cardiometabolic disease risk profile of vitamin D-deficient young adults.