Vitamin D and Inborn Errors of Metabolism

Abstract

Inborn errors of metabolism are produced by an enzymatic alteration that can be fatal or leave serious neurological sequelae. Some of these conditions require specific nutritional treatment to reverse the clinical symptoms. For phenylketonuria, patients must restrict the intake of phenylalanine; for glucose transporter deficiency syndrome type 1, the treatment is a ketogenic diet; and for classic galactosemia, galactose must be eliminated from the diet. Due to nutritional restrictions, there is an increased risk of deficiency of vitamin D and calcium, which could have an effect on plasma vitamin D levels and cause alterations in bone mineral density (BMD) among children and long-term treated patients. According to scientific evidence, the risks of vitamin D deficiency among these patients are similar to those among healthy persons. While the etiology of lower BMD is not entirely clear, it is attributed to a joint effect of underlying pathology and metabolic changes generated by diet therapy. Long-term follow-up is suggested, in addition to verifying that recommendations o critical nutrients are covered. Timely evaluation of plasmatic levels of vitamin D and BMD is suggested to avoid deficiencies or excesses and to grant a better quality of life to persons with these pathologies.