Are 50,000 International Units (Iu) Of Vitamin D Once A Week Harmful?


Asked by jerri koch

Are 50,000 International Units (Iu) Of Vitamin D Once A Week Harmful?

My doctor precribed 50,000 IU of Vitamin D, to be taken once a week due to Vitamin D deficiency. Is this safe to take? Is there any way it would be toxic?


The dose that your physician prescribed is likely safe if used on a short-term basis. The Recommended Daily Allowance (RDA) for vitamin D is 600 IU for people less than 70 years of age. Vitamin D supplementation appears to be safe when taken by mouth in doses of 4,000 IU daily (for a total of 28,000 IU per week).   Some people choose to receive vitamin D through muscular injections (typically 300,000 IU up to 3 times a year).

When vitamin D deficiency is present, at least 1,000 IU of vitamin D per day is recommended. Some research studies have shown that high doses (up to 50,000 IU daily for six weeks) are effective for treating deficiency if used on a short-term basis.

Excessive vitamin D supplementation can have serious side effects. These include allergic skin reactions, a build-up of calcium in the arteries, headaches, muscle pain, kidney or urinary stones, and gastrointestinal problems (such as nausea, vomiting, constipation, and diarrhea). Vitamin D can also affect your blood sugar and blood pressure.

Your vitamin D levels should be monitored closely during this time of high-dose supplementation, particularly because you are also taking Fosamax. Any adverse reactions should be reported to your physician immediately.

Answered by Carmen Roberts, M.S., R.D., L.D.N.