Plasma vitamin C (ascorbic acid) levels in asthmatic children.

Plasma concentration of ascorbic acid was determined in fifty-one asthmatic children and a group of matched controls. The mean ascorbic acid level of 0.54 mg/100 ml among the asthmatics was significantly lower than a mean of 0.84 mg/100 ml for controls (P less than 0.001). Ascorbic acid level was directly related to the socio-economic class (SC) since asthmatic children from SC I, II and II had significantly higher ascorbic acid levels than those from SC IV and V. There was however, no relationship between the plasma ascorbic acid level and atopy, frequency of asthmatic attacks over the previous 12 months and the duration of asthma. It is postulated that if plasma ascorbic acid level was related to the susceptibility to viral respiratory tract infections, the observed low level of the vitamin in the asthmatics would make them more liable to such infections which are capable of precipitating acute asthmatic attacks. Confirmation of our results would indicate the need for regular ascorbic acid supplement in some children with bronchial asthma.