A Multiregional Survey of Serum Vitamin D Levels among apparently healthy Nigerians – Prevalence and Risk Factors of Hypovitaminosis D

Globally, Hypovitaminosis D has been reported across age groups, with predisposing factors such as black race, older age, inactivity, diet, lack of vitamin D supplementation, indoor-outdoor lifestyle, winter/ wet season and sociocultural/socioeconomic factors. Vitamin D is an essential fat-soluble vitamin with a significant contribution to human health. The optimal level of serum vitamin D for adults' general health may be between 75 and 100 nmol/L, while there are sparse outcome data to help define a healthy or optimal level in children. In spite of the consideration for a serum vitamin D level below 25nmol/l as the lowest cutoff for vitamin D status, there are pieces of evidence that rickets can occur in infants and young children with a serum vitamin D concentration that is higher than 25nmol/l.  The study aimed to determine the prevalence and risk factors of hypovitaminosis D among apparently healthy Nigerian hospital workers and patients' caregivers and possibly provide a rationale for clinical supplementation. It was a descriptive, cross-sectional multicentre study conducted in 198 participants from the three geopolitical zones of the country between January 2019 and March 2019. A multistage sampling method was used to select the geopolitical zones and tertiary hospitals in the country while a simple random sampling method was used to select the participants from each zones. Serum vitamin D level was determined by Calbiotech Inc, kit. Over 68% of the participants had sufficient serum vitamin D levels while 30.8% had low levels, with the latter constituting the prevalence of hypovitaminosis D in this study. Only one participant had a toxic serum level of vitamin D. This study shows that about a third of the sample population had Hypovitaminosis D. This suggests a need for routine vitamin D estimation and supplementation accordingly among blacks.