# Guinea pig vitamin C calculator

> Pick the life stage to get the recommended daily vitamin C dose, food equivalents, and the pellet-freshness warning. Guinea pigs cannot synthesize vitamin C, so a measured daily supplement is required.

## Who stands behind this calculator

Written by [Patrick Li](/authors/patrick-li/). Editorially reviewed 2026-09-01 · Evidence checked 2026-09-01.

Evidence: Multiple sources agree · Evidence from this species.

No veterinarian has reviewed this page. It is educational guidance checked by the author against the cited sources — for health decisions, talk to your vet.

PetGuideCalc reserves its highest trust label for pages that a named veterinary professional has reviewed. This page does not carry that label.

The calculator computes daily vitamin C targets from published guinea pig guidance. It does not treat illness — a guinea pig that stops eating or moves stiffly needs a veterinarian, and raising a dose on your own is not the fix.

## Related tools

- [Guinea pig food guides](/guinea-pigs/) — Source-graded food safety guides for every food a guinea pig might eat.
- [All pet care tools](/tools/) — Browse every public calculator and guide by domain.

## Recommended dose by life stage

| Life stage | Daily dose | Notes |
|---|---|---|
| Healthy adult | 25 mg/day | A healthy adult needs a baseline of at least 25 mg/day, supplied by fresh greens plus a measured supplement. Weight is not the dosing axis — the daily total is what matters. |
| Juvenile, pregnant / lactating, or unwell | 30–50 mg/day | Growing, pregnant or nursing, or unwell guinea pigs need 30–50 mg/day. The upper end of the range suits late gestation, early lactation, and recovery under veterinary guidance. |

_Doses follow the locked thesis minimum (≥25 mg/d for adults) and the 30–50 mg/d range for active stages. Always pair the supplement with fresh water and ad libitum hay._

## How the dose is set

Healthy adults need at least 25 mg/day. The dose is a daily total, not a mg/kg figure — even small breeds need the full baseline.

Growth, pregnancy, and illness all raise the need into the same elevated 30–50 mg/day range, so these are merged into a single elevated-need stage: Juvenile, pregnant / lactating, or unwell.

Choose a delivery format that you can reliably measure: liquid drops, a chewable tablet, or a measured amount of high-vitamin-C vegetables. Free-choice pellets alone are not enough — vitamin C degrades in stored feed.

Opened pellets lose most of their vitamin C within 6 months (heat, humidity, and air all accelerate the loss). Either replace the bag more often or rely on a measured supplement instead.

## Vitamin C questions

**Q: Can guinea pigs make their own vitamin C?**

No. Like humans and other primates, guinea pigs lack the enzyme that converts glucose into vitamin C. They depend entirely on dietary intake — a daily supplement or measured fresh vegetables is non-negotiable.

**Q: How much vitamin C does an adult guinea pig need per day?**

At least 25 mg per day. This is the locked modern reference minimum for a healthy adult and matches the thesis-aligned guidance adopted on 2026-09-02. Elevated-need stages (juvenile, pregnant, or unwell) need 30–50 mg/day.

**Q: Do pellets provide enough vitamin C?**

Only if the bag was opened less than 6 months ago and is stored cool and dry. Vitamin C is one of the most unstable vitamins in stored feed — plan to supplement separately or rotate the bag frequently.

**Q: What vegetables are highest in vitamin C?**

Red and yellow bell pepper top the list, followed by fresh parsley, kale, and kiwi fruit. Orange is moderate; iceberg lettuce is poor. Aim for a daily rotation of two or three high-vitamin-C vegetables plus hay.

**Q: How do I spot vitamin C deficiency (scurvy)?**

Early signs: rough coat, reluctance to move, swollen joints, bleeding gums, weight loss. Scurvy in guinea pigs is a serious welfare issue — see a vet at the first sign rather than waiting for symptoms to worsen.

## Sources & standards

The locked minimum and active-stage ranges come from a thesis-aligned review of modern small-mammal nutrition sources. The pellet-stability window is the widely cited 6-month rule.

- [L-dehydroascorbic acid can substitute l-ascorbic acid as dietary vitamin C source in guinea pigs](https://doi.org/10.1016/j.redox.2015.11.003) — Frikke-Schmidt H, Tveden-Nyborg P, Lykkesfeldt J, Redox Biol, 2016.
- [Oxbow Animal Health — guinea pig nutrition](https://oxbowanimalhealth.com/blog/guinea-pig-nutrition/) — Oxbow Animal Health. Welfare- and feed-aligned guidance on daily vitamin C dosing and the 6-month pellet-freshness rule.
- [RSPCA — guinea pig welfare guidance](https://www.rspca.org.uk/adviceandwelfare/pets/rodents/guineapigs/diet) — Royal Society for the Prevention of Cruelty to Animals. UK welfare body emphasizing daily vitamin C supplementation and a hay-led diet.
- [LafeberVet — guinea pig vitamin C](https://lafeber.com/vet/guinea-pig-basics/vitamin-c/) — LafeberVet, 2024. Veterinary reference summarizing deficiency signs, supplementation routes, and dose escalation for active stages.

_Check your guinea pig with the interactive calculator: https://petguidecalc.com/guinea-pigs/vitamin-c-calculator/_