Vitamin D Deficiency Is Common in Ghana despite Abundance of Sunlight: A Multicentre Comparative Cross-Sectional Study

Abstract

Background. Vitamin D is a steroid hormone important for the normal functioning of the body. It is produced through skin exposure to sunlight and from the diet. Although Ghana is located in the tropics where sunlight is abundant, factors like culture, diet, skin pigmentation, variation in the ozone layer, and geographical area influence the optimization of vitamin D concentration. It is imperative to evaluate the interplay between sunshine exposure, proinflammatory cytokines, and mediators of vitamin D metabolism and their relationship to vitamin D status in three geographical sections among apparent healthy Ghanaians. Methods and Results. In a cross-sectional study, a total of five hundred (500) healthy blood donors from three geographical areas in Ghana were enrolled. Their age ranged from 17 to 55 years with a mean age of 27.97 ± 8.87 years. The overall prevalence rate of vitamin D deficiency was 43.6% (218/500), with 41.2% (91/221), 45.3% (63/139), and 45.7% (64/140) of vitamin D deficiency being recorded in participants from the Northern Sector (NS), Middle Belt (MB), and Southern Sector (SS), respectively. However, there were no significant differences in the proportions of vitamin D deficiency across various geographical sectors. The median 25-hydroxyvitamin D serum levels were compared among geographical areas (NS, MB, and SS) and there were no significant differences ( P = 0.275 ) after adjusting for confounding factors. 25-Hydroxyvitamin D correlated positively with corrected ionized calcium (rs = 0.622, P ≤ 0.001 ) and phosphorus (rs = 0.299, P ≤ 0.001 ) and negatively correlated with SBP (rs = −0.092, P = 0.039 ), vitamin D binding protein (VDBP) (rs = −0.421, P ≤ 0.001 ), intact parathyroid hormone (iPTH) (rs = −0.0568, rs ≤ 0.001), IFN-gamma (rs = −0.684, P ≤ 0.001 ), and TNF-alpha (rs = −0.600, P ≤ 0.001 ). After adjusting for possible confounders, not having knowledge about vitamin D foods, taking fewer vitamin D foods, and higher levels of IF-γ and IL-10 were associated with a higher risk of having vitamin D deficiency. Conclusion. The prevalence of 25-hydroxyvitamin D deficiency is high among the general adult population in Ghana despite the abundance of sunlight. Increasing knowledge on vitamin D diet coupled with a daily intake of vitamin D dietary supplements is likely to reduce the risk of developing 25-hydroxyvitamin D deficiency.

Profiling vitamin D, its mediators and proinflammatory cytokines in rheumatoid arthritis: A case–control study

“…The observed finding of no statistically significant difference in the serum levels of Vitamin D between RA patients and controls confirms a previous study by Sakyi et al, 13 who found a high prevalence of 25-hydroxyvitamin D deficiency among the general adult population in Ghana despite the abundance of sunlight. This could be attributed to dietary deficiencies and other related considerations of the general population.…”

“…This could be attributed to dietary deficiencies and other related considerations of the general population. 13 Proinflammatory cytokines including TNF-α, IL-1β, IL-6, and IFN-γ play a significant role in the pathogenesis of RA. These cytokines act synergetically leading to an increase in the rate of leukocyte recruitment to the joints, where, they maintain chronic inflammation.…”

“…KATH is the major teaching hospital in the middle belt of Ghana with more than 1000 bed capacity and serves as a referral center for other hospitals within and outside the Ashanti Region. Previous study shows high prevalence of 25‐hydroxyvitamin D deficiency among the general adult population in Ghana despite the abundance of sunlight maybe due to dietary deficiencies and other related considerations 13 …”

“…Previous study shows high prevalence of 25-hydroxyvitamin D deficiency among the general adult population in Ghana despite the abundance of sunlight maybe due to dietary deficiencies and other related considerations. 13…”

“…12 We have previously established that Th1-and Th17-related cytokines predominate in the pathophysiology of RA, with IL-6 and IL-17 being principally and differentially expressed based on the severity of the disease. 13 Vitamin D remains an essential mineral in bone development, with its role as a modulator of the immune system increasingly becoming obvious. 14 Vitamin D at the cellular level alters the immune response at the onset of infection and inflammation by reducing the level of proinflammatory cytokines produced by the macrophages and T cells.…”