Serum vitamin D profile of Nigerian children with asthma: Association with asthma severity and control

ObjectiveChildhood asthma is a chronic inflammatory airway disorder with increasing prevalence even in Africa. Vitamin D, with anti‐inflammatory and immune‐modulatory properties, may have effects on the severity and level of symptoms control in childhood asthma. We aimed to assess the serum vitamin D levels in children with asthma as related to disease severity and control in a tropical region.MethodsA hospital based comparative cross sectional study was conducted in western Nigeria. Serum vitamin D (25‐OH‐D) levels of all the children, assayed using high‐performance liquid chromatography (HPLC), were compared to the various disease severity and levels of asthma control as well as between the asthmatic and non‐asthmatic children.ResultsA total of 206 children (103 asthmatics and 103 non‐asthmatics) were recruited with a mean (SD) age of 6.6 (3.7) years. The majority (82.5%) of the children with asthma had mild intermittent form, 63.1% had well controlled symptoms while 33.0% and 3.9% had partly controlled and uncontrolled symptoms, respectively. None of the children were deficient in vitamin D. The mean (SD) serum vitamin D levels of the children with asthma (49.2 [7.2] ng/mL) was significantly lower than those without asthma (51.2 [6.9] ng/mL, P = 0.043). Varying degrees of asthma severity and levels of symptoms control were not affected by serum vitamin D levels.ConclusionChildren with asthma in Nigeria had marginally but significantly lower mean serum vitamin D levels when compared with their counterparts without asthma. However, serum vitamin D level does not seem to be associated with childhood asthma severity and control in these children with normal serum vitamin D levels.