Long-term effects of giving nursing home residents bread fortified with 125 microg (5000 IU) vitamin D(3) per daily serving.

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).