I am advocating the use of Vitamin D injections as a public health measure after large multicentre randomised trials In Australia . Vitamin D repletion in individuals presenting with vitamin D deficiency has been shown to have a positive effect on the bone biology, resulting in mineralisation of osteoid, increases in bone mineral density measurements and reduced fracture rates. Available knowledge: What is currently known about the problem, including any relevant previous studies. The main vitamin D supplements available in Australia are oral vitamin D2 and D3 preparations. The largest single Dose is Ostelin (Boots Healthcare Australia), a 1000 IU D2 preparation and 7000 IU. Other vitamin D2 preparations have lower doses (about 400 IU), and are usually combined with elemental calcium. Currently there are no parenteral megadoses of vitamin D2 or D3 preparations available in Australia. There are 2 trials already on the subject available over the internet . Vitamin D and the Elderly Medscape .Clin Endocrinol. 2005;62(3):265-281 Annual intramuscular injection of a megadose of cholecalciferol for treatment of vitamin D deficiency: efficacy and safety data (Terrence H Diamond, Kenneth W Ho, Peter G Rohl and Matthew Meerkin) I suggest that a once-yearly intramuscular cholecalciferol injection (600 000 IU) should be further investigated as a therapeutic option for treating vitamin D deficiency. This treatment is currently unavailable in Australia, and there is no ideal preparation of megadose vitamin D2 or D3 to fill this therapeutic gap. However, at a cost of $5 - $10 per injection annually compared with $35 for a monthly course of 5 Ostelin capsules daily (suggested dosages to treat vitamin D deficiency), it is remarkably cost-effective. The simple dosing regimen also allows convenient outpatient management and may improve patient compliance.