Serum vitamin D level after an annual intramuscular injection of ergocalciferol.
Heikinheimo RJ, Haavisto MV, Harju EJ, Inkovaara JA, Kaarela RH, Kolho LA, Rajala SA.
Calcif Tissue Int. 1991;49 Suppl:S87.
PMID: 1933611
An annual intramuscular injection of ergocalciferol (150,000 IU) normalized low serum (25(OH)D concentrations in elderly people for 1 year. The treatment had a slight effect on serum 24,25(OH)2D levels but no effect on 1,25(OH)2D levels.