News

To treat vitamin D deficiency higher doses may be necessary

April 23, 2012

A new study from the UK suggests that intake of oral vitamin D at 5,000 IU daily for three months has a superior effect than 2,000 IU daily in treating mild to moderate vitamin D deficiency.

In the study, 30 vitamin D deficient patients with blood levels less than 20 ng/ml were given 5,000 IU /day or 2,000 IU /day of a vitamin D supplement (1). After three months, changes in vitamin D levels and muscle strength were measured. The study results showed that after three months of receiving 2,000 IU /day vitamin D levels averaged 30 ng/ml (75 nmol/L), meaning about half the patients were still vitamin D deficient. In the 5,000- IU /day group the average vitamin D level was 45 ng/ml (114 nmol/L), which is considered to be within the normal range. In addition, 93% of the patients had levels which measured greater than the average 30 ng/ml. Among the 2,000- IU /day group, however, only 45% had levels above 30 ng/ml. In both groups, grip strength improved significantly compared to baseline, while the improvements in timed tests of sitting to standing and the 6-meter walk test also improved, but not significantly. The improvements in muscle strength did not vary with dosage: the 2,000- IU /day group showed the same improvements in grip strength as the 5,000- IU /day group did.

The researchers commented that these findings demonstrate that the administration of oral vitamin D at 5,000 IU daily for three months is superior to 2,000 IU daily in treating mild to moderate vitamin D deficiency. Muscle strength improvements, it was noted, were the most dramatic at changes in lower ranges of vitamin D levels. Although the UK Food and Nutrition Board recommends a vitamin D intake of 4,000 IU /day as the upper limit, quite a few people would still have inadequate levels at this dose, the scientists added.

References

  1. Diamond T. et al. Effect of oral cholecalciferol 2,000 versus 5,000 IU on serum vitamin D, PTH, bone and muscle strength in patients with vitamin D deficiency. Osteoporos Int. Published online March 2012.