The present study demonstrates the prevalence and impact of low vit D in males and females in a sunny country. Our key findings were: 1) High prevalence of low vit D in Qatar. In the last few years, measuring the serum level of vit D is routine in most of rheumatology, general internal medicine, cardiology, geriatric, oncology and nephrology out-patient clinics. This practice was based on the high prevalence of low vit D in countries similar to Qatar in regard with traditional, cultural and environment characteristics [8
] 2) Low vit D is significantly associated with high prevalence of DM, dyslipidemia (high total cholesterol and LDL) and CAD in males compared with females. 3) The trend for low vit D levels fell with age. 4) Low vit D is associated with 3 times increase in the rate of MI among males. 5) HTN increases the risk of CAD 8 times in the presence of low vit D regardless of gender.
After discovery of oil, the life style in the Arab Gulf region including Qatar have become progressively more modernized based on technology, sedentary activity, and unhealthy dietary patterns [25
]. These factors have led to a higher prevalence of low vit D despite of the presence of sun most of the year. Vit D deficiency is well recognized in Middle Eastern females as a result of cultural habit of remaining covered, while vit D level among males in this region remains under-reported. A recent study reported that 25(OH)D deficiency is common among otherwise healthy Middle Eastern male athletes [26
]. Assessment of vit D deficiency among health care professionals working at HGH in Qatar showed the overall mean of vit D level was 11.7 ng/ml. It was lower in females (10.3 ng/ml) than in males (13.7 ng/ml) and 97% of all participants had a mean level <30 ng/ml [27
]. Furthermore, a recent study among Qatar university students showed that 53.5% of Qatari females of college age had severe vit D deficiency and 43.6% have insufficient levels of vit D [28
] Low vit D predisposes to hypertension, DM, metabolic syndrome, heart failure and stroke [1
]. A study of male health professionals showed a 2-fold risk of MI in subjects who were vit D deficient compared with those in the normal range [36
]. The mechanism by which vit D may affect the cardiovascular system includes effects on vascular smooth muscle proliferation, inflammation and vascular calcification. Vit D deficiency activates the renin-angiotensin system leading to HTN and left ventricular hypertrophy [37
]. However, the association between vit D status and CVD is not well-defined. Epidemiologic evidence and observational studies showed potential benefits of vit D [37
]. Prospective studies demonstrated that low levels of vit D precede the development of CVD [40
]. A follow-up study based on Health Professionals showed that males with vit D deficiency (15 ng/mL had a twofold increased risk of MI, compared with those with sufficient levels of at least 30 ng/mL. Furthermore, other reports demonstrated that vit D deficiency may increase CVD risk, irrespective of established risk factors for CVD [41
The high prevalence of vit D deficiency in sunny cities especially among females and younger population emphasizes the need for a recommendation to monitor 25(OH)D, modify life style and nutritional habits [43
Limitations of the current study included retrospective nature and lack of detailed treatment information. Data were collected randomly from the central Lab records without determination of the treatment of patients or the type of subspecialty.