Distinct markers for mild vitamin B3 deficiency are lacking. To identify these, the molecular responses of white adipose tissue (WAT) to vitamin B3 withdrawal are examined...A dietary intervention is performed in male C57BL/6JRccHsd mice, in which a diet without nicotinamide riboside (NR) is compared to a diet with NR at the recommended vitamin B3 level. Both diets contain low but adequate level of tryptophan...A decreased insulin sensitivity and a shift from carbohydrate to fatty acid oxidation in response to vitamin B3 withdrawal are observed. ...The downregulation of Anp32a, Tnk2 and the upregulation of Mapk1, Map2k1, Qdpr, Mthfs, and Mthfsl are proposed as a WAT transcriptional signature marker for mild vitamin B3 deficiency.