Vitamin D deficiency is common, but new research shows that it can be treated easily and cheaply. Scientists in Boston report that they used 50,000 IU of vitamin D2 once a week to treat vitamin D deficiency in 86 patients. Within 8 weeks, the deficiency had been corrected. They prescribed 50,000 IU of vitamin D2 every other week as maintenance therapy and found that it worked well for most patients. There were no kidney stones or other side effects reported. The researchers conclude that vitamin D2 every other week worked just as well as daily vitamin D3 and is simple and inexpensive.