Abstract
Background: Vitamin D has sparked the researchers and public health interest because its deficiency and insufficiency have the potential to impact enormously on many aspects of human health. This paper presents research investigating vitamin D status among pre- and postmenopausal healthy Saudi women, examining the influence of lifestyle factors on vitamin D levels, and evaluating associated effects of vitamin D on musculoskeletal health in these healthy women. Subjects and methods: As part of the investigation, a total of 449 healthy Saudi women [age 20-82 years] were randomly recruited from the city of Jeddah, medically examined and provided urine and blood samples for assessment of biochemical parameters. Sociodemographic and lifestyle information such as sun exposure and physical activity was obtained using a standardized questionnaire. Musculoskeletal pain information was obtained through another designed questionnaire. Physical performance functions were assessed by the following three tests: get up and go (GUG), 8-feet walk (8FW), and five-time sit to stand (5-STS). Bone mineral density (BMD) was determined using dual x-ray absorptiometry (DXA). Results: The mean age was 29.1[SD 5.6] and 58.8 [SD 5.9] years for pre-and post-menopausal women, respectively. A total of 86% of women studied were vitamin D deficient (serum 25(OH) D <50 nmol/L) and 20% exhibited severe vitamin D deficiency (25(OH) D <12.5 nmol/L). The mean serum 25(OH)D was 22.6 [19.8] and 35.0 [22.1] nmol/L for pre-and post-menopausal women, respectively. Based on World Health Organization (WHO) criteria, a total of 29% of all women were osteopenic at the lumbar spine, and 29% at the femoral neck. The percentage of osteoporosis at lumbar spine site was higher than that at femur neck, being 9.1% and 4.1% respectively. Obesity was prevalent in 39% of the women studied. The mean body mass index was 25.9 [5.4] and 31.5 [5.7] kg/m2 for pre-and post-menopausal women, respectively. Although vitamin D deficiency was highly prevalent in the studied population, it was not associated with physical performance, a strong predictor of future disability. About 86.4% of women complained of bone pain, however it was not correlated to vitamin D. Conclusion: Despite abundant sun shine almost all year round, vitamin D deficiency is highly prevalent in Saudi Arabia. Limited sun exposure due to excessive heat and/or conservative clothes and obesity are among the factors contributing to this public health issue in the area. Given the high prevalence of vitamin D deficiency in our population, additional research examining the interaction between vitamin D, lifestyle factors and musculoskeletal health are warranted.