Vitamin B3 (Niacin) is essential for the following body functions:
* release energy from food
Sources of Vitamin B3:
| Food / 100g | Amount (mg) |
| Yeast extract | 73 |
| Grapenuts | 20 |
| Peanuts, plain | 19 |
| Corn flakes | 17 |
| Shiitake mushroom, dried | 15 |
Dietary Reference Intake
| Life Stage Group | RDA/AI* mg / day | Upper Limit mg / day |
| Infants 0-6 months 7-12 months | 2* 4* | Not determinable Not determinable |
| Children 1-3 years 4-8 years | 6 8 | 10 15 |
| Males 9-13 years 14-18 years 19 – >70 years | 12 16 16 | 20 30 35 |
| Females 9-13 years 14-18 years 19 – >70 years | 12 14 14 | 20 30 35 |
| Pregnancy <19 years 19 – >50 years | 18 18 | 30 35 |
| Lactation <19 years 19 – >50 years | 17 17 | 30 35 |
RDA = Recommended Dietary Allowances
AI* = Adequate Intakes
UL = Upper Limit
Vitamin B3 Deficiency
A deficiency of vitamin B3 can cause:
* pellagra (severe deficiency)
* slower metabolism, decreasing cold tolerance (mild deficiency)
Vitamin B3 Overdose
An excess of vitamin B3 (over 3g a day) can cause:
* liver damage
* dilation of the blood vessels
* kidney damage