Vitamin B3 (Niacin)
🧠 Top 20 Health Benefits of Vitamin B3 (Niacin)
- Converts food into energy — essential for ATP production via NAD/NADP
- Lowers LDL (bad) cholesterol — especially in high-dose nicotinic acid form
- Raises HDL (good) cholesterol — improves lipid profile
- Reduces triglycerides — supports heart health
- Improves circulation and blood flow
- Supports brain function and memory — protects neurons from oxidative stress
- May reduce risk of Alzheimer’s and cognitive decline
- Improves skin health — treats acne, rosacea, and inflammation
- Supports healthy digestion — aids breakdown of carbs, fats, and proteins
- Reduces inflammation throughout the body
- Supports DNA repair and cell signaling
- Helps treat pellagra — a deficiency disease causing dermatitis, diarrhea, dementia
- May improve joint mobility and reduce arthritis symptoms
- Supports mental health — may reduce depression and anxiety
- Improves insulin sensitivity — especially in type 1 diabetes
- Supports liver detoxification
- May reduce oxidative stress in cardiovascular disease
- Promotes healthy skin barrier function
- Supports hormone production (stress and sex hormones)
- May reduce risk of non-melanoma skin cancer (niacinamide form)
🔗 Interactions with Other Nutrients
Niacin works synergistically with:
- Vitamin B2 (Riboflavin) — helps convert tryptophan into niacin
- Tryptophan — an amino acid that can be converted into niacin
- Vitamin B6 & B12 — together regulate homocysteine and support brain health
- Magnesium — supports enzymatic activity of NAD/NADP
- Zinc — enhances skin and immune benefits of niacinamide
🧬 Niacin Forms & MTHFR Connection
Niacin exists in two main forms:
| Form | Function | Notes |
|---|---|---|
| Nicotinic acid | Lowers cholesterol, improves circulation | May cause flushing at high doses |
| Niacinamide (nicotinamide) | Anti-inflammatory, skin and brain support | No flushing; used in skincare and neuroprotection |
MTHFR Connection:
- Niacin is not directly processed by MTHFR, but it supports methylation indirectly by helping recycle NAD/NADP, which are vital for cellular metabolism.
- People with MTHFR mutations may benefit from niacinamide to reduce oxidative stress and support detox pathways.
🥩 Top Food Sources of Vitamin B3 (per serving)
| Food | Niacin (mg) | Serving Size |
|---|---|---|
| Tuna (yellowfin) | 37.5 mg | 6 oz |
| Chicken breast | 13.7 mg | 100 g |
| Pork chops | 13.6 mg | 100 g |
| Liver (beef) | 14.7 mg | 85 g |
| Salmon | 7.9 mg | 100 g |
| Turkey | 8.1 mg | 100 g |
| Peanuts (dry roasted) | 12.1 mg | 100 g |
| Mushrooms (portabella) | 7.6 mg | 1 cup |
| Brown rice (cooked) | 5.2 mg | 1 cup |
| Sunflower seeds | 8.3 mg | 100 g |
| Avocados | 3.5 mg | 100 g |
| Green peas (cooked) | 3.2 mg | 1 cup |
The recommended daily intake is 16 mg for men and 14 mg for women. Therapeutic doses (for cholesterol) may exceed 1,000 mg/day — but only under medical supervision.
⚠️ Niacin Side Effects & Overdose Risks
Niacin is water-soluble, but high doses (especially supplements) can cause:
- Flushing — warmth, redness, itching (common with nicotinic acid)
- Nausea, vomiting, diarrhea
- Liver damage — especially with sustained-release forms
- Elevated blood sugar — caution in type 2 diabetes
- Dizziness or arrhythmia — in overdose cases
- Increased risk of heart disease — recent studies link excess niacin breakdown (4PY) to vascular inflammation
The tolerable upper intake level (UL) is 35 mg/day for adults from supplements. Food sources are safe and well-regulated.