Vitamin D and falls — the dosage conundrum

Falls are a major health problem in elderly individuals. Although intensive physical therapy and management of hazards in the home can reduce falls by 25%, long-term practicality limits their use. Interest in vitamin D as a medical therapy has led to many trials; however, results using daily oral doses of vitamin D have been inconsistent. In the past 5 years, studies on the effect of bolus doses of vitamin D have produced surprising results. Bolus doses of vitamin D, given annually (at a dose of 300,000 IU or 500,000 IU) or monthly (at a dose of 24,000 IU or 60,000 IU) — equivalent to approximate daily doses of 800 IU, 1400 IU and 2,000 IU — result in a significant increase in the number of falls and fractures associated with serum levels of 25-hydroxyvitamin D greater than 40–45 ng/ml (equivalent to 100–112 nmol/l). These unexpected results show increased falls and fractures are adverse events related to vitamin D administration. Until further safety data is available, bolus dosing or daily doses should not exceed 3,000 IU and serum levels of 25-hydroxyvitamin D should not exceed 40–45 ng/ml (equivalent to 100–112 nmol/l) in elderly individuals.