The difference was even more prominent in the Summer months, during which the most severe degree of vitamin D deficiency was found in 34.5% of the 150 ID patients but only in 0.7% of the 192 control subjects.
These findings partially explain the high fracture rate of ID patients and are mostly due to insufficient exposure to sunlight, which is the predominant factor in vitamin D production.
The investigators also found that currently available and inexpensive treatments, in the form of a minimum of 800 Units of vitamin D3 daily, are safe and effective in restoring normal vitamin D levels.
Diagnosis and treatment of vitamin D deficiency should become standard care for patients with intellectual disabilities.
A similar strategy may be required in other psychiatric populations who spend excessive time indoors and will also be at risk for fractures.
The study, funded by the Baily Thomas Charitable Fund, is published by the British Journal of Psychiatry and has been the object of a press release by the journal.