Regular Consumption of Both Vitamin D– and Calcium- and Vitamin D–Fortified Yogurt Drink Is Equally Accompanied by Lowered Blood Lipoprotein (a) and Elevated Apoprotein A1 in Subjects with Type 2 Diabetes: A Randomized Clinical Trial

OBJECTIVE: Cardiovascular disease (CVD) is the major morbidity and cause of death in diabetic subjects. Observational studies have shown the association of low vitamin D status with poor glycemic control, atherogenic lipid profile, and CVD. However, the possible link between circulating 25-hydroxycholecalciferol and apoproteins (Apo A1 and B) and the atherogenic lipoprotein (a) [Lp(a)] has not been documented to date. METHODS: Ninety subjects with type 2 diabetes (T2D) aged 30-60 years from both sexes were randomly allocated to one of the 3 groups to receive 2 bottles a day of either (1) plain doogh (PD; containing 150 mg calcium and no detectable vitamin D/250 mL); (2) vitamin D-fortified doogh (DD; containing 150 mg calcium and 500 IU vitamin D/250 mL); or (3) calcium- and vitamin D-fortified doogh (CDD; containing 250 mg calcium and 500 IU vitamin D/250 mL) for 12 weeks. Anthropometric, dietary, and laboratory assessments, including Apo A1, Apo B, and Lp(a), were done. RESULTS: Improvement of vitamin D status in DD and CDD groups, compared to PD, resulted in a significant increase in Apo A1 (mean changes 0.22 ± 0.38, 0.20 ± 0.27 and 0.01 ± 0.35 g/L, respectively, p = 0.047) and a significant decrease in serum Lp(a) (mean changes -0.08 ± 0.30, -0.08 ± 0.31, and 0.14 ± 0.25 μmol/L, respectively, p = 0.011). There was no significant difference between DD and CDD groups. Serum Apo B did not change significantly in any of the groups. CONCLUSIONS: Significant amelioration of serum Apo A1 and Lp(a) following improvement of vitamin D status in T2D subjects may have preventive implications against long-term diabetic complications, notably CVD. This trial was registered at ClinicalTrials.gov as NTC01229891.