A 25-Hydroxycholecalciferol-Fortified Dairy Drink Is More Effective at Raising a Marker of Postprandial Vitamin D Status than Cholecalciferol in Men with Suboptimal Vitamin D Status.

One strategy for improving population vitamin D status is consumption of fortified foods. However, the effects of dairy products fortified with different vitamin D isoforms on postprandial vitamin D status and metabolic outcomes have not been addressed. We investigated whether consumption of dairy drinks fortified with either 25-hydroxycholecalciferol [25(OH)D] or cholecalciferol (vitamin D) had differential effects on 24-h circulating plasma 25(OH)D concentration (a marker of vitamin D status) and cardiometabolic risk markers. A randomized, controlled, 3-way crossover, double-blind, postprandial study was conducted in 17 men with suboptimal vitamin D status [mean ± SEM age: 49 ± 3 y; body mass index (in kg/m): 26.4 ± 0.6; and plasma 25(OH)D concentration: 31.7 ± 3.4 nmol/L]. They were randomly assigned to consume 3 different test meals (4.54 MJ, 51 g fat, 125 g carbohydrate, and 23 g protein), which contained either a nonfortified dairy drink (control), 20 μg 25(OH)D-fortified (+HyD) dairy drink, or 20 μg vitamin D-fortified (+D) dairy drink with toasted bread and jam on different occasions, separated by a 2-wk washout. Plasma 25(OH)D concentrations and cardiometabolic risk markers, including vascular stiffness, serum lipids, and inflammatory markers, were measured frequently within 8 h postprandially and 24 h after the dairy drink was consumed. Plasma 25(OH)D concentrations (the primary outcome) were significantly higher after the +HyD dairy drink was consumed compared with +D and control ( = 0.019), which was reflected in the 1.5-fold and 1.8-fold greater incremental area under the curve for the 0-8 h response, respectively. The change in plasma 25(OH)D concentrations from baseline to 24 h for the +HyD dairy drink was also 0.9-fold higher than the +D dairy drink and 4.4-fold higher than the control ( < 0.0001), which were not significantly different from each other. The dairy drink fortified with 25(OH)D was more effective at raising plasma 25(OH)D concentrations postprandially than was the dairy drink fortified with vitamin D in men with suboptimal vitamin D status. This trial was registered at clinicaltrials.gov as NCT02535910.