RESUMEN
Our previous studies [Siddiqui et al 1990] revealed that prevalence of lactose intolerance was high amongst adult females as compared to males and intolerance increased with age. This study was extended to infants and lactose tolerance test was done on thirty infants and lactose 1g/kg body weight was given to each infant orally. Heel capillary blood samples were taken at 0.30, 60 and 90 minutes and blood glucose and galactose were estimated. An increase in blood glucose and galactose of at least 20 mg% was the criteria for intolerance. Intolerance of lactose was found in 4 out of 11 female infants below 6 months while 5 out of 5 female infants above 6 months were intolerant to lactose. In case of male infants below 6 months all the 7 male infants were tolerant while above 6 months 3 out of 7 were intolerant. There was a significant increase in the percentage of intolerance and malabsorption after 6 months of age. It was concluded from the study that lactose malabsorption is common in Faisalabad area and is quite common in female infants and increase with age