Medium doses of daily vitamin D decrease falls and higher doses of daily vitamin D3 increase falls: A randomized...

Area of Science:

• Gerontology
• Nutritional Science
• Public Health

Background:

• Falls are a significant health concern for the aging population.
• Low vitamin D levels are linked to increased fall rates, but previous studies on vitamin D supplementation have yielded mixed results.
• Existing meta-analyses suggest minimal or no effect of vitamin D on fall reduction.

Purpose of the Study:

• To investigate the effect of various daily oral doses of vitamin D on serum 25-hydroxyvitamin D (25OHD) levels and fall rates in elderly women.
• To determine the relationship between serum 25OHD levels and fall incidence.
• To identify optimal vitamin D dosage and serum levels for fall prevention in older women.

Main Methods:

• A 12-month, double-blind, randomized placebo-controlled trial involving elderly women (mean age 66) with baseline serum 25OHD < 20 ng/mL.
• Participants were randomized to one of seven daily oral vitamin D doses or a placebo.
• Fall history was collected at baseline, and fall events were recorded every 3 months. Serum 25OHD was measured at 12 months.

Main Results:

• The effect of vitamin D on falls exhibited a U-shaped curve concerning both dosage and serum 25OHD levels.
• Medium vitamin D doses (1600-3200 IU) significantly decreased falls (p=0.020), whereas low (400-800 IU) and high doses (4000-4800 IU) showed no significant reduction compared to placebo.
• Maximum fall reduction was observed at serum 25OHD levels of 32-38 ng/mL. Faller rates increased when serum 25OHD exceeded 40-45 ng/mL, particularly in women with a prior fall history.

Conclusions:

• Vitamin D supplementation has a complex, dose-dependent effect on fall prevention in elderly women, with a U-shaped relationship observed.
• Optimal fall reduction is associated with achieving serum 25OHD levels between 32-38 ng/mL.
• Current Tolerable Upper Intake Levels (TUL) for vitamin D may need re-evaluation for elderly women, especially those with a history of falls, as high doses can increase fall risk.