Three centuries ago, long sea voyages left crews exhausted, with bleeding gums, covered in bruises. In 1747, naval surgeon James Lind did something bold: he gave lemons and oranges to scorbutic sailors and observed rapid recovery. This simple trial, often cited as one of the first controlled trials, would reveal the shadow of a missing nutrient — what we now call vitamin C. See the historical analysis of the 1747 experiment and its methodological lessons.
Symptoms (mild deficit → scurvy)
Vitamin C deficiency can be subtle at first ("mild deficit") then progress to scurvy if intake remains insufficient for several weeks.
- Fatigue, irritability, weakness
- Dry and rough skin, small petechiae or perifollicular bleeding, "corkscrew" hair
- Easy bruising, bleeding gums (gingivitis), poor wound healing
- Muscle and joint pain, bone pain (children)
- In advanced forms: anemia, more frequent infections, diffuse hemorrhages (scurvy)
For a synthetic clinical overview: the reference page on vitamin C deficiency and scurvy from MSD Manuals (English) describes typical signs and their progression.
Bleeding gums, unexplained bruising, wounds that heal poorly, or diffuse pain with very poor dietary intakes of fruits/vegetables: seek medical advice. An assessment can look for other causes (hematological, nutritional) in addition to a vitamin C deficit.
Tests and benchmarks
The diagnosis remains clinical and nutritional (symptoms + dietary history). Tests can help:
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Plasma ascorbic acid (sensitive to recent intakes)
- < 11 µmol/L (~0.2 mg/dL): severe deficit compatible with scurvy
- < 23 µmol/L (~0.4 mg/dL): probable deficiency
- > 50 µmol/L: generally adequate status These thresholds are commonly cited in clinical reviews and syntheses (see the vitamin C deficiency – clinical benchmarks fact sheet).
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Leukocyte vitamin C: better correlated with tissue stores, but rarely available in routine.
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Pre-analytical: vitamin C is labile (light, heat) → samples protected and processed quickly.
For limits and practical uses of tests, the NIH ODS professional fact sheet on vitamin C reminds that plasma mainly reflects recent intake and must be interpreted with clinical context.
Vitamin C-rich foods
Vitamin C is abundant in common foods. Usual examples (indicative values per serving):
- Raw red bell pepper (~½ large): very rich
- Kiwi (1–2 pieces), strawberry (1 bowl), citrus (orange, lemon)
- Black currants, papaya, guava (very rich)
- Broccoli, kale, tomato, potato (especially mashed/baked)
For precise values per food, rely on the Ciqual composition table (France) or the FoodData Central tool (USDA).
Practical tips: vitamin C is sensitive to heat and prolonged storage. Favor raw vegetables or short cooking (steaming, sautéing) and consume fresh/frozen products quickly.
Doses and tolerance
Daily intake guidelines (adults):
- France (ANSES): 110 mg/day for healthy adults — see national recommended intakes.
- Europe (EFSA): 110 mg/day (men), 95 mg/day (women) as population reference value.
- United States (NIH): 90 mg/day men, 75 mg/day women, with +35 mg/day advised for smokers (see the NIH ODS fact sheet).
Tolerance / safety:
- Upper limit (UL): in the United States, 2,000 mg/day (adults) according to the ODS NIH reference. On the European side, EFSA has not set a formal UL for lack of robust data, but notes gastrointestinal disorders at high doses.
- Frequent adverse effects: diarrhea, abdominal cramps, nausea when the dose is high or fractionated too rarely.
- Kidney stones (oxalate): an increased risk is discussed in predisposed individuals and at very high chronic doses; stay within reasonable doses and personalize according to your history (see the Safety section of the ODS fact sheet).
- Interactions: vitamin C increases non-heme iron absorption (useful if low intakes, caution in hemochromatosis). It can also interfere with some biological tests. In case of treatment or pathology, follow medical advice.
Start with dietary intakes. If a documented deficit is probable, fractionated doses (e.g., 100–200 mg, 1–2 times/day) are often better tolerated than a single gram at once.
FAQ
What are the first signs of deficiency? Fatigue, irritability, easy bruising, dry/rough skin, gingivitis/bleeding gums, slow healing. See the clinical summary table.
How long does it take to develop "mild scurvy"? Generally several weeks of very low intakes, depending on initial stores and context (smoking, very restrictive diet, malabsorption).
Should I supplement systematically? No. Priority to diet. A short supplementation can help if intake remains insufficient or if symptoms/the context suggest it (see recommended intakes and EFSA guidelines).
Does vitamin C cure colds? Evidence doesn't show a net effect to prevent colds in the general population. A slight shortening of duration is possible in some, especially in case of intense efforts or low status (see ODS synthesis).
Which form to choose: ascorbic acid, ascorbate, "liposomal"? Classic ascorbic acid is effective and economical; variants have not demonstrated major clinical advantages at equivalent doses for most people.
Vitamin C and iron: how to optimize? Combine vitamin C with a meal containing non-heme iron (legumes, whole grains) improves absorption. No need to overdose.
Sources
- Discovery of citrus fruits against scurvy – historical analysis (James Lind Library)
- Vitamin C deficiency and scurvy – clinical synthesis (MSD Manuals, EN)
- Vitamin C – professional fact sheet (NIH Office of Dietary Supplements)
- EFSA – Dietary reference values for vitamin C (PRI)
- ANSES – Vitamin C recommended nutritional intakes
- Ciqual food composition table (vitamin C per food)
