Hypovitaminosis D in the Middle East and North Africa

Abstract

Background: The Middle East and North Africa (MENA) region registers some of the highest rates of hypovitaminosis D worldwide.

 

Aim: We systematically reviewed the prevalence of hypovitaminosis D, rickets and osteomalacia, their predictors and impact on major outcomes, in the region.

Methods: Medline, Pubmed and Embase search engines, entering keywords and concepts, combined with individual countries of interest, were used. Search was limited years 2000–2012; and review articles were used for the period preceding year 2000.

Results: Rickets and osteomalacia still occur in this sunny region. Hypovitaminosis D prevails, with rates varying 30–90%, considering a desirable serum 25 hydroxy-vitamin D [25(OH)D] of 20 ng/ml. Advancing age, female gender, multi-parity, clothing style, season, socio-economic status and urban living are recognized predictors of hypovitaminosis D in adults. Prolonged breastfeeding without vitamin D supplementation and low dietary calcium intake are the recognized risk factors for rickets and hypovitaminosis D in children.. Associations with pain score and disease activity in rheumatologic disorders, viral load and interleukins in hepatitis C, BMI, lipids and insulin sensitivity, blood pressure, heart failure and mortality are described. Sun exposure in adults decreased prevalence of metabolic syndrome in one study. Few randomized vitamin D trials revealed that the majority of mothers or children failed to achieve a desirable 25(OH)D level, even with doses by far exceeding current recommendations. A trial in adolescent girls reveals substantial bone and lean mass increments.

Conclusion: Hypovitaminosis D is prevalent in MENA. The lack of populations based studies, gaps in studies in infants, pre-pubertal children and pregnant women, hinder the development of region specific guidelines and constitute a major obstacle to impact this chronic and most often subclinical disease.

Keywords: :

• risk factors
• prevalence
• osteomalacia
• rickets
• musculoskeletal outcomes
• infections
• pleotropic
• genetics polymorphisms
• region specific guidelines
• policy

Disclosure of Potential Conflicts of Interest

No potential conflict of interest was disclosed.

Acknowledgments

The authors would like to thank Ms Aida Farha, Medical Information Specialist, Saab Medical Library, American University of Beirut, for her advice and assistance in designing comprehensive and complex searches of the various medical literature resources and for the provision of select articles and Mr. Samir Hanoun for the art work. This review was in part supported by an educational grant from the Medical Practice Plan at the American University of Beirut and the Lebanese National Council for Scientific Research.

Notes

† These authors contributed equally to this work