Nutritional infantile vitamin B12 deficiency: pathobiochemical considerations in seven patients

In infants with nutritional vitamin B12 deficiency, early clinical symptoms follow a consistent pattern with irritability, failure to thrive, apathy and anorexia, accompanied by consistent refusal of solid foods and developmental regression. Vitamin B12 acts as a cofactor in the remethylation of homocysteine and the degradation of methylmalonyl-CoA. The biochemical mechanisms by which vitamin B12 deficiency leads to neurological damage are poorly understood. We report on seven breast fed infants with nutritional vitamin B12 deficiency due to maternal vegan diet. …