Correlates of hypovitaminosis d among postmenopausal women in Kiambu County, Kenya: a community survey

Abstract

Introduction: Vitamin D deficiency remains a major global health issue yet new research shows it has a role in reducing the risk of communicable and non-communicable diseases. In Kenya, there is scanty information on the prevalence of hypovitaminosis D and its associated factors. The objective of this study was to determine the prevalence and correlates of hypovitaminosis D amongst postmenopausal women in a Kenyan peri urban population.

Methods: We carried out a community based cross sectional survey involving 254 post-menopausal women in Kiambu County, Kenya from October 2017 to February 2018. Multi-stage random sampling approach was adopted where households were selected after sampling sub-counties and enumeration areas. A structured questionnaire was administered, and physical examination done on recruited participants by the principal investigator and research assistants. Weight and height of the participants were measured, and bone mineral density was determined using Dual energy X-ray absorptiometry (DXA). All participants had blood samples taken to assay for serum 25-hydroxyvitamin D (25(OH)D) levels. SPSS statistical software version 21.0, SPSS Inc was used for data analysis.

Results: The mean age of the women was 64.6 years with a range of between 50 and 95 years. 58.7% (149) of respondents had 25(OH)D serum levels below 30 ng/ml. The prevalence of Vitamin D deficiency was 18.9% (48), Vitamin D insufficiency 39.8% (101) while 41.3% (105) of women had normal Vitamin D levels. There was a positive association between hypovitaminosis D and advancing age (p-value=0.042), lower education levels (p=0.006), Body mass Index (BMI) (p-value=0.043) and osteoporosis (p=0.000). Occupation, marital status and wealth status had no association with the serum vitamin D levels

Conclusions: The prevalence of hypovitaminosis D in Kenya is high and is associated with advancing age, lower education levels, BMI and osteoporosis. Early detection and prevention of hypovitaminosis D may be the key to reduce osteoporosis in postmenopausal women in Kenya.