Vitamin D in the Eastern Mediterranean Region: A Technical Guide

Vitamin D is an essential, fat-soluble micronutrient that is either naturally present in few foods, added intentionally to some foods or found in dietary supplements. It plays numerous vital roles in the maintenance of the organ systems in the human body, in addition to its known role in bone health maintenance by facilitating the absorption of calcium and phosphorous. Vitamin D deficiency (VDD) has become a major public health concern, particularly in countries undergoing a rapid nutrition transition with a shift in dietary habits and lifestyle, characterized by high consumption of processed foods, and an indoor lifestyle. VDD has shown implications on nutrition and health, including bone health, myopathy, cardiovascular and heart diseases (strokes, myocardial infarction, heart failure), diabetes, depression, as well as implications during pregnancy. The most vulnerable to VDD are infants, teenagers, pregnant women, older adults, people with limited sun exposure, people with darker skin, people with reduced fat absorption, obese people, people who underwent gastric bypass surgeries and vegans.Moreover, not only does VDD have health consequences, but so does excessive levels of vitamin D in the body. In fact, vitamin D toxicity has been associated with hypercalcemia, calcification of soft tissues, growth failure, fatigue and irritability, irregular heart rhythms, renal failure and in some cases mortality.Although the daily needs of vitamin D can be met by sun exposure, VDD remains prevalent globally. As for the Eastern Mediterranean Region (EMR), and according to the most recent national and regional data, VDD was found to be prevalent, with its prevalence ranging between 8% and 81% among under five children, between 16.2% and 95.5% among women of reproductive age (WRA) and between 13.6% and 93.9% among pregnant women.Globally, the treatment and management of VDD includes promoting a healthy, diverse and nutritiousdiet; supplementation, after consulting with the physician or healthcare practitioner; ensuring appropriate food fortification; ensuring sufficient sun exposure; providing awareness programs and propereducation; involving the food industry at the level of product reformulation; supporting research to assess and oversee the impact of supplementation programs and fortification strategies in practice. While some countries and regions in the EMR, such as Lebanon and the Gulf Cooperation Council (GCC), have developed their own guidelines, the general recommendations for vitamin D in the EMR highlight the following three key points: 1) promoting reasonable sun exposure, encouraging healthy eating habits and enforcing fortification within safe margins; 2) testing for VDD is only recommended for symptomatic individuals and those at risk; and 3) no recommendations are present for population-wide screening for low vitamin D levels.