Authors: Pollard Charley-Lea, Gibb Zamira, Swegen Aleona, Lawson Edwina F, Grupen Christopher G
Journal: Journal of animal physiology and animal nutrition
Summary
Recent evidence from human and animal research suggests that NAD+ (nicotinamide adenine dinucleotide) deficiency may contribute to embryonic loss and congenital abnormalities, yet little is understood about NAD+ metabolism in horses despite early embryonic death being a significant cause of pregnancy failure in mares. Pollard and colleagues administered a 5 g oral dose of nicotinic acid to four mares and tracked NAD+ metabolites in plasma and urine using mass spectrometry, collecting blood samples over 22 hours and urine samples at intervals to map absorption, metabolism and excretion patterns. Nicotinic acid was rapidly absorbed within 15 minutes, with plasma levels of key NAD+ precursors—particularly nicotinamide and nicotinic acid adenine dinucleotide (NaAD)—reaching significantly elevated concentrations at 30 minutes and remaining 6–9 times above baseline even 22 hours post-administration, whilst excretion of metabolites began within 3 hours via urine. Although extracellular NAD+ itself remained undetectable in plasma, the sustained elevation of NaAD strongly suggests that intracellular NAD+ availability was substantially improved, indicating that nicotinic acid supplementation does enhance NAD+ bioavailability in mares. For equine practitioners involved in reproductive management, these findings suggest potential merit in investigating nicotinic acid supplementation during early gestation when embryonic metabolic demands peak, though further research is needed to establish optimal dosing protocols and clinical efficacy in preventing early pregnancy loss.
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Practical Takeaways
- •Nicotinic acid supplementation may improve NAD+ bioavailability in mares during early pregnancy when embryonic development creates peak NAD+ demand
- •The rapid absorption and sustained elevation of NAD+ metabolites supports the potential use of nicotinic acid supplementation as a strategy to reduce early embryonic death in breeding mares
- •Further research is needed to determine optimal dosing protocols and clinical efficacy for preventing pregnancy loss in equine practice
Key Findings
- •Nicotinic acid was rapidly absorbed into peripheral blood within 15 minutes of oral administration at 5g dose
- •Plasma concentrations of nicotinamide and nicotinic acid adenine dinucleotide remained significantly elevated at 22 hours (6-fold and 9-fold respectively above baseline)
- •Urinary excretion of NAD+ metabolites peaked at 3 hours post-administration
- •Sustained elevation of NAD+ precursors in plasma suggests cellular NAD+ levels are boosted despite extracellular NAD+ remaining undetectable