High-dose cholecalciferol effectively treats vitamin D deficiency Medwire

By Joanna Lyford, 29 March 2012
Osteoporos Int 2012; Advance online publication

Individuals who received cholecalciferol 5000 IU/daily were much more likely than those given 2000 IU/daily to achieve the target serum 25-hydroxyvitamin D (25OHD) level, and may as a consequence have better bone and muscle outcomes, the researchers suggest.

Vitamin D deficiency can cause abnormal bone metabolism and reduced muscle function, both of which are linked with falls and fractures.

In this pilot study, Terry Diamond (St George Hospital, Kogarah, Australia) and co-workers sought to determine the optimal therapeutic dose of cholecalciferol required to normalise serum 25OHD levels and the relationship with parathyroid hormone (PTH) levels, bone turnover, and muscle strength.

They recruited 30 consecutive patients with serum 25OHD levels of 50 nmol/L or less and randomly assigned them to take oral cholecalciferol 2000 IU or 5000 IU daily for 3 months. In all, 26 patients completed the study and were included in the final analysis.

Between baseline and 3 months, mean serum 25OHD levels rose by 82.7% in the lower-dose group and by 219.5% in the higher-dose group, Diamond's team reports in Osteoporosis International.

The target 25OHD level was set at 75 nmol/L or above. This was achieved by 45.4% of the lower-dose group and by 93.3% of the higher-dose group, indicating a statistically significant treatment effect.

All patients achieved the more modest 25OHD target of 50 nmol/L or above, say the authors, who also calculated that the "reflexion point" at which PTH levels increased above the normal range was 63.8 nmol/L of 25OHD.

Finally, biochemical markers of bone turnover and physical tests of muscle strength had all improved after 3 months of therapy, although only some of the changes were statistically significant.

Diamond's team concludes: "These data suggest that higher doses of oral cholecalciferol (5000 IU daily for 3 months) may be required to achieve optimal serum 25OHD concentrations in most patients with vitamin D deficiency.

"These dosages are safe and effective and result in improvements in PTH activity and muscle strength… This study also supports a serum 25OHD concentration of at least 60 nmol/L for preventing hyperparathyroidism."

MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
– – – – – – – – –
All started with less than 20 nanograms
3 months of vitamin D
45% of those getting 2,000 IU got > 30 ng
93% of those getting 5,000 IU got > 30 ng

See also Vitamin D Life

• Many ways to get 2X increased response from the same dose
  this study did not appear to have tried any of the ways