ABSTRACT
BACKGROUND: Vitamin D insufficiency contributes to muscle weakness and a higher risk of falls in older adults. OBJECTIVES: This study explored the impact of vitamin D supplementation on self-reported falls and physical function in older adults with low vitamin D levels and a recent fall history. MATERIALS AND METHODS: Twenty-five older adults ≥ 70 years with two or more falls during the past year, low vitamin D blood levels (≥10 ng/ml and < 30 ng/mL), and slow gait speed (1.2 m/s) participated in a 6-month vitamin D supplementation (800 IU/day) study. A modified version of the Morse Fall Scale questionnaire was used to assess frequency of falls over one-year prior to study enrollment. Functional outcomes (short physical performance battery, handgrip strength, gait Timed Up and Go, and six-minute walk), and vitamin D levels were assessed at baseline and 6-month follow-up. RESULTS: Based on diaries and pill counts, participants were generally adherent to the intervention (6 of 7 days per week). Supplementation with 800 IU/day of vitamin D for 6 months increased blood vitamin D levels from 23.25±4.8 ng/ml to 29.13±6.9 ng/ml (p<0.001). Self-reported number of falls decreased from an average of 3.76 ± 2.2 falls in one-year to 0.76 plusmn; 1.4 falls (p <0.0001) over the 6-month intervention. No changes in functional outcome measures were observed. CONCLUSIONS: Vitamin D supplementation at the currently recommended dose of 800 IU/day increased blood vitamin D levels and reduced frequency of falls in older adults with low vitamin D levels and a recent fall history.
