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Comment & Response |

Proposed Guidelines for Future Vitamin D Studies

Ayse Nur Tufan, MD1; Fatih Tufan, MD2
[+] Author Affiliations
1Division of Rheumatology, Department of Internal Medicine, Uludag University, Bursa, Turkey
2Division of Geriatrics, Department of Internal Medicine, Istanbul University, Istanbul, Turkey
JAMA Intern Med. 2016;176(2):280. doi:10.1001/jamainternmed.2015.7971.
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To the Editor We read with interest the article by Hansen et al1 suggesting that neither low-dose nor high-dose cholecalciferol have beneficial effects on bone or muscle health. We have comments about this well-designed and well-performed study.

First, as the authors underlined, secondary hyperparathyroidism (SH) occurs in only 10% to 33% of people with vitamin D insufficiency and subjects without SH might not benefit from vitamin D treatment. Although the authors did not report the rate of SH in their study, median vitamin D and parathyroid hormone levels indicate that SH was infrequent in these patients. Thus, this study may be considered a contribution to the growing body of evidence indicating that supplementing what is sufficient is not beneficial, if not harmful.24


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February 1, 2016
William B. Grant, PhD; Luca Mascitelli, MD; Mark R. Goldstein, MD, FACP
1Sunlight, Nutrition, and Health Research Center, San Francisco, California
2Comando Brigata Alpina “Julia,” Multinational Land Force, Medical Service, Udine, Italy
3NCH Physician Group, Naples, Florida
JAMA Intern Med. 2016;176(2):279-280. doi:10.1001/jamainternmed.2015.7968.
February 1, 2016
Rudruidee Karnchanasorn, MD; Horng-Yih Ou, MD, PhD; Ken C. Chiu, MD
1Division of Endocrinology, Department of Medicine, University of Kansas Medical Center, Kansas City
2Division of Endocrinology and Metabolism, Department of Internal Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
3Department of Clinical Diabetes, Endocrinology, and Metabolism, City of Hope National Medical Center, Duarte, California
JAMA Intern Med. 2016;176(2):280-281. doi:10.1001/jamainternmed.2015.7974.
February 1, 2016
Karen E. Hansen, MD, MS; Michael G. Johnson, MS
1Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison
JAMA Intern Med. 2016;176(2):281-282. doi:10.1001/jamainternmed.2015.7983.
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