Nicotinamide Riboside Protects Against Heat Stress–Induced Testicular Damage and Improves Boar Fertility: Preclinical Findings

Synopsis

Heat stress (HS) from rising global temperatures negatively affects male fertility, damaging the testes and reducing semen quality. This study examined how HS alters testicular NAD+ metabolism and whether nicotinamide riboside (NR)—a vitamin B3–derived NAD+ precursor—can protect against this damage. In boars exposed to high temperatures, NAD+ deficiency was identified as a key marker of testicular injury and poor sperm production. Supplementation with NR restored NAD+ levels, improved spermatogenesis, and enhanced semen quality. NR also reduced oxidative stress and inflammation triggered by heat exposure. These findings demonstrate that NR supplementation supports testicular metabolism and fertility under environmental stress, offering a promising nutritional strategy to counteract heat-induced reproductive decline.

Journal

Molecular Nutrition & Food Research