Vitamin D deficiency may be associated with allergies in sub-Saharan Africa

Abstract

BackgroundThough the consensus is that vitamin D deficiency is associated with allergies, virtually no study investigates this association in a sub-Saharan African setting. MethodsTo investigate the association between vitamin D deficiency and allergies in this setting, we recruited 42 allergic patients (60% adults vs. 40% children) and 20 controls (45% adults vs. 55% children). Allergies were confirmed in symptomatic patients by measuring circulating allergens-specific IgE antibodies (Proteome Tech kits), whereas blood concentration of vitamin D was measured using the total 25-hydroxyvitamin D kit (BioMérieux). Results88% (37/42) of allergic patients had low vitamin D. Only 25% of (5/20) non-allergic controls had low serum vitamin D levels. Vitamin D insufficiency was significantly higher in allergic patients than non-allergic controls (odds ratio = 22.2; relative risk: 3.5; χ2 = 24.7; P < 0.0001). Low vitamin D serum concentration prevalence was similar in both children and adult patients (87% (13/15) vs. 85.2% (23/27) respectively). In children (odds ratio: 26; relative risk: 4.3; χ2 = 11.1; p-value < 0.001), like in adults (odds ratio: 72; relative risk: 3.8; χ2 = 20.7; P < 0.0001), low serum vitamin D level was significantly associated to allergies. ConclusionA strong association was found between low serum vitamin D level and allergies, suggesting that vitamin D deficiency may be linked to allergy development in sub-Saharan African settings. More extensive studies need to be done to confirm our findings. Key messageThe development of allergies in sub-Saharan Africa may be linked to vitamin D insufficiency.