Vitamin B6 Neonatal Toxicity

Abstract

Vitamin B6 is a micronutrient required by the body. It acts as a coenzyme in biochemical reactions. Vitamin B6 toxicity is not caused by the intake of food-based sources. The few reported cases of vitamin B6 toxicity are always caused by overdosing of nutritional supplements. Chronic toxicity typically occurs with peripheral neuropathy such as paraesthesia, ataxia, and imbalance, paradoxically mimicking vitamin B6 deficiency. However, the prognosis is favorable, and symptoms usually show improvement once excessive vitamin B6 levels return to the physiological range. We report a newborn presenting with diffuse tremor at birth, interpreted as secondary to the mother's intake of high doses of a supplement containing vitamin B6 during pregnancy and breastfeeding. As expected, the newborn's serum levels of vitamin B6 were high. The tremors disappeared when the maternal supplement was stopped.

Figure 1

Chemical structure and derivation of the molecules with vitamin B6 action [20].