When and How to Diagnose and Treat Vitamin D Deficiency in Adults: A Practical and Clinical Update

Abstract

Vitamin D deficiency is considered a major public health concern. Inadequate sun exposure, limited oral intake, and impaired intestinal absorption are common risk factors for vitamin D deficiency. An increasing amount of research is aimed at answering questions regarding the most convenient test that can assess vitamin D status, the indications for screening, and finally the utility of treatments for vitamin D deficiency. Our review outlines practical strategies to diagnose and treat vitamin D deficiency in adults. This study was undertaken in the PubMed and the Google Scholar databases in April 2018 without limitation as to the publication period. Vitamin D status is determined by measuring the 25-hydroxyvitamin D serum concentration. However, this technique has several limitations. Determining the accurate thresholds for vitamin D deficiency is still a matter of debate. Only individuals at risk for vitamin D deficiency should be screened. The symptoms of vitamin D deficiency are unspecific and very common. Therefore, physicians may easily suspect vitamin D deficiency, measure 25-hydroxyvitamin D levels, and sometimes overprescribe supplementation. Hypovitaminosis D could rarely be treated by increasing consumption of foods naturally containing and fortified with vitamin D. Special attention should be given to vitamin D supplementation to prevent adverse effects. No safe and well-defined threshold of ultraviolet exposure allows adequate vitamin D synthesis without increasing the risk of skin cancer. Unanimous and decisive guidelines are urgently needed to improve knowledge and practices related to vitamin D deficiency.

Keywords:

• deficiency
• risk factors
• screening
• supplementation
• toxicity
• treatment
• vitamin D

Acknowledgments

The authors are most grateful to Dr. Dany Daham and Mr. Andres Rodrigues for editing the manuscript.

Declaration of interest

The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

About the authors

Antoine Aoun, MD PhD, Specialist in Family Medicine and Assistant Professor of Human Nutrition at the Faculty of Nursing and Health Sciences at Notre Dame University-Louaize. Dr. Aoun's major research interests include eating behaviors and nutritional supplementation.

Jessica Maalouf, MS, Human Nutrition, Notre Dame University-Louaize. Ms. Maalouf's major research interests include nutrition and supplementation.

Myriam Fahed, MS, Human Nutrition, Notre Dame University-Louaize. Ms. Fahed's major research interests include nutrition and supplementation.

Flora El Jabbour, MS, Nutrition and Food Service Management, Lebanese University. Mrs. El Jabbour's major research interests include nutritional supplementation and food security.

Table 6. Drug interaction with vitamin D.