Objective: Vitamin D deficiency is common among women despite abundant sunshine in Saudi Arabia. No local study has evaluated the seasonal vitamin D level among hospitalized menopausal and postmenopausal Saudi women. The aim of this study was to estimate the prevalence of vitamin D deficiency among menopausal and postmenopausal in Saudi Arabia during summer and winter.
Methods: Data were retrospectively collected for 1556 female patients (>19 years) during their hospital visits between January 2009 and December 2009 in Riyadh, Saudi Arabia. The patients were divided into two groups 659 (42%) and 897 (58%) patients during summer and winter respectively. The summer group was subdivided into menopausal 425 (27%) (1949 years) and postmenopausal 234 (15%) (≥50 years); and in winter, 543 (35%) and 354 (23%) respectively. Serum levels of 25-hydoxy vitamin D (25OH VIT D) were measured by HPLC method.
Results: The prevalence of hypovitaminosis (<37 nmol/l) in menopausal and postmenopausal women was 18 and 7.6% during summer; 26 and 14% during winter respectively. There was a significant difference between the mean of vitamin D level of menopausal (33.3±33) and postmenopausal (44.4±35) women during summer (P<0.0001) and (28.5±27) and (36.3±28) during winter (P<0.0001) respectively. The between and within seasonal vitamin D variations were observed among menopausal and postmenopausal women (P<0.05). The between seasonal variations represented a 14% increase in vitamin D level for menopausal and 18.5% for postmenopausal women and that for within seasonal variation were 25 and 21% increase respectively.
Conclusion: A higher prevalence of vitamin D deficiency among the hospitalized menopausal and postmenopausal Saudi women was observed in winter. Seasonal variation was also observed between and within this population. Clinicians should consider determination of vitamin D level in these women especially menopausal and advice proper supplementations.