NAD+ Adult Dosing Recommendations
Standard Dietary Intake (Niacin as NAD+ Precursor)
For general health maintenance through dietary niacin (the established NAD+ precursor), adult males require 16 mg/day and adult females require 14 mg/day, with higher amounts needed during pregnancy (18 mg/day) and lactation (16 mg/day). 1
- These recommendations come from the American College of Nutrition and represent the Dietary Reference Intake (DRI) for niacin, which the body converts to NAD+ 2
- Parenteral nutrition dosing is standardized at 40 mg/day 1
Safety Upper Limits for NAD+ Precursors
Nicotinamide (Does Not Cause Flushing)
- The upper intake limit is 12.5 mg/kg body weight/day, approximately 900 mg/day for adults 1, 2
- No adverse effects were observed at doses up to 25 mg/kg body weight/day in prolonged studies 1
- This form does not cause the flushing side effects seen with nicotinic acid 2, 3
Nicotinic Acid (Causes Flushing)
- Upper limit is only 10 mg/day for free nicotinic acid due to flushing effects starting at 30 mg/day 1
- Clinical doses for hypercholesterolemia treatment can reach 3 g/day, but this is 300-fold above the safety threshold 1
Nicotinamide Mononucleotide (NMN) Supplementation
For NMN specifically, doses of 250-1250 mg daily have been studied and found safe in clinical trials, with 300-900 mg daily showing dose-dependent increases in blood NAD+ levels. 4, 5, 6
Evidence-Based Dosing:
- 250 mg daily for 6-12 weeks elevated blood NAD+ levels and showed nominal improvements in gait speed and grip strength in older men 6
- 300-900 mg daily for 60 days produced significant dose-dependent increases in NAD+ concentration, with higher doses generally producing greater effects 4
- 1250 mg daily for 4 weeks was safe and well-tolerated with no severe adverse events in healthy adults aged 20-65 years 5
Important Caveats:
- There is substantial interindividual variability (coefficient of variation 29.2-113.3%) in NAD+ response to NMN supplementation 4
- The median effective NAD+ concentration increase for functional improvements (walking distance, quality of life) was approximately 13.5-15.7 nmol/L 4
- Monitoring blood NAD+ levels may be valuable for personalizing dosage, though this is not standard clinical practice 4
Nicotinamide Riboside (NR) Supplementation
For nicotinamide riboside, 500 mg twice daily (1000 mg total daily) is the dose being investigated for cardiovascular benefits in adults over 50 years with elevated blood pressure. 7
- This dosing regimen is being studied for 3 months to assess effects on systolic blood pressure and arterial stiffness 7
- NR may be particularly important for neuronal NAD+ synthesis compared to other precursors 8
Practical Dosing Algorithm
For general health maintenance: Use dietary niacin at DRI levels (14-16 mg/day) through food sources including fortified foods, meat, poultry, fish, nuts, and legumes 1, 2
For NAD+ supplementation in healthy adults: Start with NMN 250-300 mg daily, which has demonstrated safety and efficacy 4, 6
For more robust NAD+ elevation: Consider NMN 600-900 mg daily, which produces greater dose-dependent increases in blood NAD+ 4
Maximum studied safe dose: NMN up to 1250 mg daily has been proven safe for 4 weeks 5
Alternative option: Nicotinamide riboside 500 mg twice daily (1000 mg total) for cardiovascular and aging-related concerns 7
Side Effects and Monitoring
- NMN does not cause flushing, unlike nicotinic acid 2, 3
- Potential gastrointestinal effects include nausea, vomiting, and diarrhea 9
- Urinary metabolites (N-methyl-nicotinamide and N-methyl-2-pyridone-carboxamide) can assess niacin status if monitoring is desired 1, 2, 9
- Insufficient safety data exists for pregnancy and lactation 9