Background: Research on nicotinic acid, commonly known as niacin, shows that this vitamin (classified as B۳) is a potent antioxidant that helps shield the body from oxidative stress.
Niacin serves as a building block for NAD⁺ and NADP⁺, two essential coenzymes that participate in a wide range of metabolic reactions, both energy producing and biosynthetic, and help maintain the cell’s redox balance. By curbing lipid peroxidation and limiting the formation of harmful reactive oxygen species, niacin supports cellular integrity. In addition, it enhances mitochondrial efficiency and reduces inflammation. Methods: In this study, nicotinic acid was administered orally at a dosage of ۱,۰۰۰ mg per ۲۰ kg of body weight every ۲۴ hours. Blood and semen samples were collected at two week intervals from seven adult male dogs for ۵۶ days. Baseline samples, obtained during the first week, served as controls. Subsequent assessments included the evaluation of total antioxidant capacity,
malondialdehyde concentration, testosterone levels, and various
sperm quality parameters. Results: This study evaluated serum and seminal plasma antioxidant capacity,
malondialdehyde levels, serum testosterone, serum inhibin, and
sperm quality following oral administration of nicotinic acid. Results indicated upward trends in serum testosterone and inhibin, with significant increases in inhibin between several sampling days, notably from baseline to days ۴۲ and ۵۶ (P < ۰.۰۵). Serum
total antioxidant capacity rose significantly at multiple time points, while serum and seminal plasma
malondialdehyde decreased, reaching statistical significance in selected comparisons. Seminal plasma antioxidant capacity and semen quality parameters did not differ significantly over time. Overall, nicotinic acid supplementation appeared to enhance serum antioxidant status, elevate inhibin levels, and reduce oxidative stress markers, without affecting fresh semen quality in dogs. Conclusion: In conclusion, nicotinic acid is not only an essential nutrient but also an effective antioxidant that protects against oxidative damage.