Niacin (Vitamin B3) is involved in over 400 enzyme reactions in the body, making it one of the most broadly important B vitamins. It plays central roles in energy metabolism, DNA repair, and the production of steroid hormones. Niacin is also essential for maintaining healthy skin and mucous membranes — the body's first line of defense against infection.
Guinea pigs can synthesize some niacin from the amino acid tryptophan, but this conversion pathway is not efficient enough to meet all their needs. Dietary niacin from hay, pellets, and fresh vegetables fills the gap. Cecal bacteria also produce niacin, which guinea pigs absorb through coprophagy.
Niacin deficiency in guinea pigs is uncommon with a varied diet, but can develop if a guinea pig is on a restricted or poor-quality diet for an extended period.
Guinea pigs need approximately 10 to 30mg of niacin per kilogram of diet. Hay, fresh greens, and quality pellets provide adequate amounts.
0.04% of daily nutrient intake
Vitamin B3 (Niacin) makes up 0.04% of your guinea pig's total daily nutritional requirements by weight. That's a tiny amount — but it matters.
Loss of appetite, weight loss, diarrhea, inflamed or ulcerated mouth and tongue, rough skin, and general malaise. Severe deficiency leads to a condition similar to pellagra in humans.
Niacin is water-soluble and excess is excreted. Very high doses from supplements (not food) can theoretically cause liver stress, but this is not a concern from dietary sources.
| Life Stage | Size | Min | Max | Unit | Notes |
|---|---|---|---|---|---|
| Adult | — | 10 | 30 | mg/kg diet | Per kilogram of diet dry matter. Dietary sources plus partial synthesis from tryptophan meet needs. |
Source: NRC 1995, general veterinary consensus
