Researchers have shown that 50,000 International Units (IU) of vitamin D2, given weekly for eight weeks, effectively treats vitamin D deficiency.
The new study has been done by researchers at Boston University School of Medicine.
Vitamin D2 is a mainstay for the prevention and treatment of vitamin D deficiency in children and adults.
Continued treatment with the same dose of vitamin D2 every other week for up to six years after the initial eight-week period prevents vitamin D deficiency from recurring with no toxicity.
Vitamin D is essential for strong bones because it helps the body absorb calcium and phosphorus from the food we eat.
Vitamin D deficiency can lead to rickets in children and the painful bone disease osteomalacia in adults. Vitamin D deficiency can also cause osteoporosis and has been linked to increased risk of cancer, heart disease, diabetes, autoimmune diseases and infectious diseases including influenza.
Of the 86 patients researchers studied, 41 patients who were vitamin D deficient received eight weeks of 50,000 IU of vitamin D2 weekly prior to starting maintenance therapy.
For those patients, the mean pre-treatment 25-hydroxyvitamin D status (25(OH)D) level was 19 ng/ml, which increased to 37 ng/ml after eight weeks of weekly therapy. These patients were then treated with 50,000 IU of vitamin D2 every other week and had a mean final 25(OH)D level of 47 ng/ml.
For the 45 patients who received only maintenance therapy of 50,000 IU of vitamin D2 every two weeks, the mean pre-treatment 25(OH)D level was 27 ng/ml and the mean final level was 47 ng/ml.
"Vitamin D2 is effective in raising 25(OH)D levels when given in physiologic and pharmacologic doses and is a simple method to treat and prevent vitamin D deficiency," said senior author Michael F. Holick, PhD, MD, director of the Bone Healthcare Clinic and the Vitamin D, Skin and Bone Research Laboratory at Boston University School of Medicine.
"While treating and preventing vitamin D deficiency, these large doses of vitamin D2 do not lead to vitamin D toxicity," he added.
According to Holick, this is the first study demonstrating the efficacy of a prescription therapy to prevent vitamin D deficiency long-term in routine clinical practice.
The study appears online in the journal Archives of Internal Medicine.