Recommended vitamin D intake may be too low
MedWire News: Recommended vitamin D intake may be too low to achieve optimal reduction of falls and fracture risk, study findings suggest.
Heike Bischoff-Ferrari (University Hospital Zurich, Switzerland) and co-authors studied patient data from eight randomized controlled trials of falls (n=2426) and 12 of non-vertebral fracture risk (n=42,279), vitamin D dose, and 25-hydroxyvitamin D (25[OH]D) level achieved.
As reported in the journal Osteoporosis International, the optimal dose for reduction of falls and fractures was found to be at the highest dose tested sufficiently to date, 700–1000 IU vitamin D per day. Benefits were also found for an average 25(OH)D level of 75–110 nmol/l, which would be achieved by an average dose of 1800–4000 IU vitamin D per day.
This is significantly greater than the current recommended daily dose of 200–600 IU, the team notes.
The 75–110 nmol/l vitamin D daily dose was also found to provide the greatest benefit for cardiovascular health and reduced risk for colorectal cancer, without any evidence of increased risk for hypercalcemia.
“The reliable evidence that excess vitamin D can cause hypercalcemia in generally healthy adults comes from daily intakes of vitamin D greater than 100,000 IU or serum 25(OH)D exceeding 240 nmol/l, which are far higher than those necessary to achieve the benefits,” Bischoff-Ferrari et al note.
The researchers conclude: “The evidence from randomized trials suggests that the dose of vitamin D supplement needed to bring the large majority of persons to the range of optimal serum 25(OH)D may be in the range of 1,800 to 4,000 IU per day.
“Further work is needed, taking into account subject and environment factors, to better define the doses that will achieve the optimal blood levels in the large majority of the population.”
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By Lynda Williams