EC Microbiology

Introduction: Vitamin D deficiency is considered to be a medical concern that is prevalent worldwide. Despite that normal mean vitamin D (25(OH)D) concentrations in adult and elderly individuals are found in regions of North America, Asia Pacific, and Europe (which is about 20.4 to 28.9 ng per ml), the regions of Middle East and North Africa (MENA) are considered to have the lowest concentrations of vitamin D (which is about 13.6 to 15.2 ng/ml), for the same age groups, despite having relatively high sun exposure.

Aim of Work: In this review, we will discuss the most recent evidence regarding vitamin D deficiency in the Middle East, and its management in primary care.

Methodology: We did a systematic search for vitamin D deficiency in the Middle East, and its management in primary care using PubMed search engine (http://www.ncbi.nlm.nih.gov/) and Google Scholar search engine (https://scholar.google.com).

Conclusions:

In the MENA region, the IOM RDA of 600 IU/day is not sufficient to bring 25(OH)D to the desirable level of 20 ng/ ml; higher doses of 1750-2000 IU/day may be needed. In addition to the dose, the baseline 25(OH)D level significantly affects the response to vitamin D re- placement. These findings provide the needed information to formulate MENA specific vitamin D guidelines. Additional long-term safety and high-quality studies using intermediate to high vitamin D doses are required, and more solid evidence on the effect of vitamin D on various skeletal and extra-skeletal outcomes is still needed.

Keywords: Vitamin D Deficiency; The Middle East; Management in Primary Care

1. Hilger J., et al. “A systematic review of vitamin D status in populations worldwide”. British Journal of Nutrition1 (2014): 23-45.
2. Arabi A., et al. “Hypovitaminosis D in developing countries-prevalence, risk factors and outcomes”. Nature Reviews Endocrinology 6.10 (2010): 550-561.
3. Bassil D., et al. “Hypovitaminosis D in the Middle East and North Africa”. Dermatoendocrinology2 (2013): 274-298.
4. Gannagé-Yared MH., et al. “Prevalence and predictors of vitamin D inadequacy amongst Lebanese osteoporotic women”. British Journal of Nutrition4 (2009): 487-491.v
5. Barry EL., et al. “Genetic variants in CYP2R1, CYP24A1, and VDR modify the efficacy of vitamin D3 supplementation for increasing serum 25-hydroxyvitamin D levels in a randomized controlled trial”. Journal of Clinical Endocrinology and Metabolism10 (2014): E213-E217.
6. Dawson-Hughes B., et al. “IOF position statement: vitamin D recommendations for older adults”. Osteoporosis International7 (2010): 1151-1154.
7. Ross C TC., et al. “Dietary reference intakes for calcium and vitamin D”. The National Academies Press, Washington, DC (2011): 662.
8. Holick MF., et al. “Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline”. Journal of Clinical Endocrinology and Metabolism 96.7 (2011): 1911-1930.
9. Rosen CJ. “Clinical practice. Vitamin D insufficiency”. New England Journal of Medicine3 (2011): 248-254.
10. Zittermann A., et al. “Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies”. American Journal of Clinical Nutrition1 (2012): 91-100.
11. Prentice A. “Vitamin D deficiency: a global perspective”. Nutrition Reviews2 (2008): S153-S164.
12. El-Kaissi S and Sherbeeni S. “Vitamin D Deficiency in the Middle East and Its Health Consequences for Adults”. Nutrition Health In Vitamin D: Physiology, Molecular Biology, and Clinical Applications, ed. Michael Holick. New York (NY): Humana Press (2010).
13. Holick MF. “Vitamin D deficiency”. New England Journal of Medicine3 (2007): 266-281.
14. Shea MK., et al. “Genetic and non-genetic correlates of vitamins K and D”. European Journal of Clinical Nutrition4 (2009): 458-464.v
15. Signorello LB., et al. “Common variation in vitamin D pathway genes predicts circulating 25-hydroxyvitamin D Levels among African Americans”. PLoS One12 (2011): e28623.
16. Gallagher JC., et al. “Dose response to vitamin D supplementation in postmenopausal women: a randomized trial”. Annals of Internal Medicine6 (2012): 425-437.
17. Shab-Bidar S., et al. “Serum 25 (OH) D response to vitamin D3 supplementation: a meta-regression analysis”. Nutrition9 (2014): 975-985.
18. Cashman KD., et al. “A systematic review and meta-regression analysis of the vitamin D intake-serum 25-hydroxyvitamin D relationship to inform European recommendations”. British Journal of Nutrition 11 (2011): 1638-1648.
19. El Hajj Fuleihan G., et al. “A randomized trial investigating the impact of vitamin D replacement on indices of insulin resistance in elderly overweight subjects”. American Journal of Clinical Nutrition (2016): ajcn132589
20. Sebaaly A., et al. “The extra-skeletal actions of vitamin. D - Myths and facts”. Lebanese Medical Journal2 (2015): 87-93.
21. Guyatt GH., et al. “GRADE guidelines: 7. Rating the quality of evidence-inconsistency”. Journal of Clinical Epidemiology12 (2011): 1294-1302.
22. Vieth R. “Critique of the considerations for establishing the tolerable upper intake level for vitamin D: critical need for revision upwards”. Journal of Nutrition4 (2006): 1117-1122.
23. Heaney RP., et al. “Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol”. American Journal of Clinical Nutrition1 (2003): 204-210.