Worldwide more than 2 % of newborn children are born with birth defects. Malformations are among the leading causes of death in Sub-Saharan Africa. In Uganda, the number of deaths of malformed children is currently even increasing. Very little is known about the causes of these malformations, but genetic defects are considered to be a possible trigger. The presence of at least three of the following congenital abnormalities: vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities; is generally referred to as the VACTERL-Associaion. Scientists from the Victor Chang Cardiac Research Institute in Sydney have now found a link between a genetic-associated deficiency in the nicotinamide adenine dinucleotide (NAD) co-enzyme and those malformations in the VACTERL group. NAD is an important cofactor for several redox reactions and is involved in a large number of reactions, such as the citrate cycle. NAD can be synthesized in the kynurenine metabolism from the essential amino acid L-tryptophan and from the dietary precursor niacin (vitamin B3). Sources of niacin include for example lean meat (such as lean beef, veal and pork or poultry) and fish (e.g. anchovies, tuna, salmon and mackerel), green vegetables, peanuts and mushrooms. Whole wheat bread and coffee also contain niacin.
The experts are discussing whether a highly dosed supplementation of niacin to pregnant women could prevent developmental problems in unborn children. In their study, they identified two gene mutations that diminish NAD synthesis by defective enzymes in kynurenine metabolism. The experimental research on mice revealed that the resulting lack of NAD impairs the development of the embryo and frequently leads to malformations. That suggests that the mutation of many other genes involved in NAD synthesis could have the same effect. However the supplementation of niacin during pregnancy of the mice prevented embryo defects, suggesting that NAD could be synthesized through the precursor and its pathway. As a feasible example to a possible niacin supplementation, serves the successes in the administration of folic acid to women of childbearing age for the prevention of neural tube defects (e.g. cleft spine). Folic acid is particularly involved in cell division processes and is therefore essential for embryogenesis. The dietary reference value for niacin recommends a 2 to 3 mg higher niacin intake during pregnancy and lactation. However, it remains to be seen if further results support a general niacin supplementation for pregnant women to prevent embryonic malformations.
H. Shi et al. NAD Deficiency, Congenital Malformations, and Niacin Supplementation. New England Journal of Medicine, August 2017; 377(6), pp. 544-552. Available via: http://www.nejm.org/doi/full/10.1056/NEJMoa1616361