Vitamin B3 (niacin) for fertility

On this page

1. What is vitamin B3?
2. Function and how it works
3. Fertility benefits
4. Recommended daily dose
5. Food sources
6. Cautions and contraindications
7. My Fertility Guide
8. Related pages

1. What is vitamin B3?

Vitamin B3 (niacin) is a water-soluble B vitamin that plays a fundamental role in energy production and the use of oxygen by cells. It exists in two main forms: nicotinic acid and nicotinamide (niacinamide), both of which can be converted in the body to NAD and NADP — coenzymes involved in over 400 enzymatic reactions, more than any other vitamin-derived coenzyme.

Reference ranges and recommended intakes vary from country to country — always interpret guidance against the recommendations of your own healthcare authority.

2. Function and how it works

Vitamin B3 supports fertility in several ways:

1. Energy production. NAD is essential for the conversion of glucose, fatty acids and amino acids into ATP, the body's energy currency.
2. DNA repair. NAD is required for the repair of damaged DNA — particularly important for protecting the DNA in eggs and sperm from oxidative damage.
3. Steroid hormone synthesis. NADP is required for the production of steroid hormones, including oestrogens, progesterone and testosterone.
4. Mitochondrial function. NAD levels decline with age, contributing to reduced egg quality. NMN, a precursor of NAD, is increasingly used to address this in older women.

3. Fertility benefits

Adequate vitamin B3 supports the energy and DNA-repair processes essential for ovulation, sperm production, fertilisation and embryonic development. Niacin is particularly relevant in older couples, where declining NAD levels contribute to reduced fertility.

4. Recommended daily dose

I recommend a daily dose of 15–20 mg of vitamin B3, typically obtained as part of a good-quality prenatal or B-complex supplement. Therapeutic doses of niacin (500 mg or more) are sometimes used to lower cholesterol but are not appropriate for fertility support.

5. Food sources

Niacin is found in a wide range of foods:

1. Whole grains
2. Nuts and seeds
3. Meat and poultry
4. Oily fish (salmon, tuna, mackerel)
5. Eggs and dairy products
6. Dried fruits

6. Cautions and contraindications

1. The nicotinic acid form of B3 in high doses (500 mg or more) can cause flushing — a harmless but uncomfortable warmth and reddening of the skin. The nicotinamide (niacinamide) form does not cause flushing and is preferable for general supplementation.
2. Very high doses can affect liver function — therapeutic doses should always be supervised.
3. Always consult with a fertility specialist or your doctor before starting any new supplement regime.

7. My Fertility Guide

8. Related pages

• Fertility supplements directory
• Vitamin B1 (thiamin)
• Vitamin B2 (riboflavin)
• NMN (nicotinamide mononucleotide)
• Folic acid (vitamin B9)