According to a Clinical research study published in the Canadian Medical Association Journal patient who did not have a history of bone loss or vitamin D deficiency, took dose of vitamin D daily about 8,000-12,000 IU for over 24 months, As a result, he had very high levels of calcium in the blood which left him with significant kidney damage.
The recommended daily allowance of vitamin D is 400-1000 IU, with 800-2000 IU recommended for adults at high-risk of osteoporosis and for older adults.
Although vitamin D toxicity is rare owing to a large therapeutic range, its widespread availability in various over-the-counter formulations may pose a substantial risk to uninformed patients.
Calcium levels may get worse before getting better in patients even after cessation of supplements, as vitamin D is fat soluble.
Patients should be better informed about the risks regarding the unfettered use of vitamin D.
FROM AWARD-WINNING AUTHOR DR GOVIND SHUKLA, NUTRITION EXPERT

Govind Shukla, Specializes in Pharmacology, Toxicology, Nutraceuticals & Herbal Drugs has published More than 100 research papers in National & International Journals. He is also a reviewer of International Journal of Pharmacology & pharmacotherapeutics, Chief editor of IJPNR Journal & Freelance Medical Writer for Different publication Groups including Lambert Academic Publishing Saarbrucken, Germany.