Background: In older adults, a serum 25-hydroxyvitamin D [25(OH)D] concentration >75 nmol/L lowers the risk of fracture. An oral intake of 125 microg (5000 IU) vitamin D(3)/d may be required to achieve this target.
Objective: The objective was to characterize the safety and efficacy of fortifying bread with a biologically meaningful amount of vitamin D(3).
Design: In a single-arm design, 45 nursing home residents consumed one bun daily that had been fortified with 125 microg (5000 IU) vitamin D(3) and 320 mg elemental calcium.
Results: The initial mean (+/-SD) serum 25(OH)D concentration was 28.5 +/- 10.8 nmol/L. After 12 mo, the 25(OH)D concentration was 125.6 +/- 38.8 nmol/L, and it exceeded 74 nmol/L in 92% of the patients. At every 3-mo follow-up, serum parathyroid hormone was lower than at baseline (P = 0.001). No changes in serum calcium or cases of hypercalcemia were observed at the follow-up assessments. Both mean total urinary calcium and the mean urinary calcium-creatinine ratio increased from baseline at one follow-up time point (P < 0.05). Between baseline and the 12-mo visit, z scores for bone mineral density at the lumbar spine and the hip both increased significantly (P < 0.001).
Conclusions: Fortification of bread with much more vitamin D than used previously produced no evident adverse effects on sun-deprived nursing home residents and improved bone density measures. Fortification of bread with 5000 IU vitamin D(3)/d provided reasonable assurance that vitamin D-deficient older adults attained a serum 25(OH)D concentration greater than the desirable objective of >75 nmol/L. This trial was registered at (ClinicalTrials.gov) as: NCT00789503.