Ascorbic acid

What it is

Ascorbic acid is vitamin C, a water-soluble nutrient that humans cannot make for themselves, so it has to come from food or a product. Chemically it is L-ascorbic acid, molecular formula C6H8O6. It is also a licensed medicine: in the United States an ascorbic acid injection is approved for short-term treatment of scurvy when the oral route cannot be used. Large doses are additionally used off-label by intravenous infusion in intensive care and oncology, and by mouth as an over-the-counter supplement.

What the research says

The evidence is strongest for the one thing the drug is approved for: replacing vitamin C in scurvy. Beyond that the record is mostly negative. Regular supplementation does not reduce how often adults in the general community catch colds, though it shortens episodes slightly; vitamin C started after symptoms begin has shown no consistent effect. Randomised trials have found no benefit in advanced cancer, no reduction in cardiovascular events, no improvement in organ failure in sepsis, and in the largest sepsis trial a higher rate of death or persistent organ dysfunction than placebo. Documented harms include oxalate nephropathy and kidney stones, and haemolysis in people with G6PD deficiency.

Evidence grade: Mixed evidence.

How it works

Drug class: Water-soluble vitamin used as replacement therapy; antiscorbutic agent (vitamin C)

Ascorbic acid replenishes the body's pool of vitamin C. The US label states plainly that the exact mechanism by which it treats scurvy is unknown, and that treatment is thought to work by restoring that body pool. Independently, a pharmacology review describes vitamin C as an electron donor that acts as an antioxidant and as a cofactor for a family of biosynthetic and gene-regulatory enzymes, which is why deficiency damages connective tissue and immune function. (Source 1)

What it is used for

• The US label approves ascorbic acid injection for short-term treatment of scurvy, up to one week, in adults and children from 5 months of age when oral dosing is not possible, insufficient or contraindicated. It is explicitly not approved for vitamin C deficiency without signs and symptoms of scurvy. Case series and case reports describe symptoms resolving after repletion, but there is no modern placebo-controlled outcome trial. Evidence: established. (Source 2)
• A Cochrane review of twenty-nine trial comparisons in 11,306 participants found a pooled risk ratio for catching a cold of 0.97 with a confidence interval touching 1.00, which the authors read as a failure to reduce incidence. A subgroup of people under brief severe physical stress was the exception. Evidence: not-supported. (Source 3)
• In the same Cochrane review, regular supplementation shortened colds by 8% in adults and 14% in children. These are small average effects from trials of varied quality, and they do not apply to starting vitamin C once a cold has begun. Evidence: limited. (Source 3)
• Seven comparisons covering 3249 episodes found no consistent effect of therapeutic vitamin C on how long colds lasted or how bad they were. Evidence: not-supported. (Source 3)
• Three randomised trials point the same way or worse. CITRIS-ALI (167 patients) found no significant difference in organ failure scores or inflammatory markers. VITAMINS (216 patients) found no significant difference in time alive and free of vasopressors. LOVIT (872 patients) found death or persistent organ dysfunction in 44.5% on vitamin C versus 38.5% on placebo, a risk ratio of 1.21. Evidence: not-supported. (Source 4)
• A double-blind randomised trial in 100 patients with advanced colorectal cancer who had never had chemotherapy compared 10 g of vitamin C daily with placebo and found no advantage for time to disease progression or survival, and no objective tumour responses. Evidence: not-supported. (Source 5)
• In the Physicians' Health Study II, 14,641 male physicians took 500 mg of vitamin C daily or placebo for a mean of 8 years. Vitamin C had no significant effect on major cardiovascular events (hazard ratio 0.99, 95% CI 0.89-1.11) or on total mortality. Evidence: not-supported. (Source 6)
• A single-centre, open-label equivalence randomised trial in 440 adults with iron deficiency anaemia found adding 200 mg of vitamin C to each oral iron dose gave the same haemoglobin and ferritin recovery as iron alone, meeting the prespecified equivalence criterion. Evidence: not-supported. (Source 7)

Interactions

• Oral iron supplements (clinical trial): Vitamin C is widely taken with iron tablets to help absorption, but a single-centre, open-label randomised equivalence trial in iron deficiency anaemia found iron alone worked just as well, so routinely pairing them added nothing measurable in that setting. (Source 7)
• Warfarin (case reports): Isolated case reports have suggested vitamin C interferes with warfarin's anticoagulant effect, but a study at up to 1,000 mg a day for two weeks found no effect. Standard anticoagulation monitoring should continue. (Source 8)
• Erythromycin, kanamycin, streptomycin, doxycycline, lincomycin and bleomycin (label): The label states ascorbic acid may reduce the activity of several antibiotics, and that bleomycin is inactivated by ascorbic acid in the test tube rather than in people. (Source 9)

Stopping it

• There is no vitamin C withdrawal syndrome in the literature reached here. What the label does require is stopping for harm: ascorbic acid injection is to be discontinued in anyone who develops oxalate nephropathy, and the course is capped at one week in any case. (Source 10)
• Treatment is also to be stopped if haemolysis is suspected in someone with G6PD deficiency. (Source 11)

What goes wrong

In the largest sepsis trial, intravenous vitamin C increased the risk of death or persistent organ dysfunction compared with placebo. (Source 12)

• Randomized trial, Moderate certainty.
• Size: 872 patients randomised (435 vitamin C, 437 control)
• Who: Adults in an ICU no longer than 24 hours with proven or suspected infection, receiving a vasopressor.
• How long: Infusion every 6 hours for up to 96 hours; outcome at day 28.
• Result: Primary outcome in 191 of 429 (44.5%) on vitamin C versus 167 of 434 (38.5%) on placebo; risk ratio 1.21 (95% CI 1.04 to 1.40; P = 0.01). Death at 28 days 35.4% versus 31.6% (RR 1.17, 95% CI 0.98 to 1.40)
• Funding: Lotte and John Hecht Memorial Foundation (independent of a manufacturer)

The primary outcome occurred in 191 of 429 patients (44.5%) in the vitamin C group and in 167 of 434 patients (38.5%) in the control group (risk ratio, 1.21; 95% confidence interval [CI], 1.04 to 1.40; P = 0.01).

Higher total and supplemental vitamin C intake was associated with more kidney stones in men but not in women. (Source 13)

• Cohort study, Low certainty.
• Size: 156,735 women and 40,536 men; 6,245 incident kidney stones.
• Who: Nurses' Health Study I and II and Health Professionals Follow-up Study participants.
• How long: Median follow-up 11.3 to 11.7 years.
• Result: In men, hazard ratios across total intake categories were 1.00, 1.19 (95% CI 0.99-1.46), 1.15 (95% CI 0.93-1.42), 1.29 (95% CI 1.04-1.60) and 1.43 (95% CI 1.15-1.79), P for trend = 0.005; supplemental intake 1,000 mg/d or more HR 1.19 (95% CI 1.01-1.40). No significant association in women; dietary intake alone was not associated.
• Funding: not stated.

Total and supplemental vitamin C intake was significantly associated with higher risk for incident kidney stones in men, but not in women.

The US label warns that prolonged high-dose ascorbic acid has caused acute and chronic oxalate nephropathy. (Source 10)

• Official position, Certainty not rated.
• Size: Not applicable; regulatory warning text.
• Who: Patients receiving ascorbic acid injection, particularly those with renal disease, a history of oxalate stones, older people and children under 2 years.
• How long: Risk tied to prolonged administration; the label caps treatment at one week.
• Result: No rate is given; the label instructs monitoring of renal function in patients at increased risk and discontinuation if oxalate nephropathy develops.
• Funding: not applicable.

Acute and chronic oxalate nephropathy have been reported with prolonged administration of high doses of ascorbic acid.

In a single published case report of one patient, a septic man given intravenous vitamin C developed biopsy-confirmed calcium oxalate crystal deposition in the kidney and needed dialysis. (Source 14)

• Case report, Very low certainty.
• Size: One patient (single case report)
• Who: A 63-year-old man with sepsis of pulmonary origin in a community hospital.
• How long: Intravenous vitamin C, hydrocortisone and thiamine for 4 days from day 19.
• Result: On day 23 renal replacement therapy was required at an estimated glomerular filtration rate of 7 mL/min; biopsy showed extensive acute tubular necrosis with intratubular calcium oxalate crystal.
• Funding: not stated.

Limit of this finding: This is one patient, so it shows that this can happen, not how often it happens. The journal's abstract template labels the narrative "Data sources" and "Data extraction", the headings a systematic review uses; nothing here was searched for or pooled. The man already had kidney failure before the vitamin C was started, which the report itself flags. The grammatical slip "despite a having developed" is the source's own wording and has been left as printed.

Renal biopsy revealed extensive acute tubular necrosis associated with the presence of intratubular crystal of calcium oxalate.

Pharmacological-dose ascorbic acid infusion caused severe haemolysis and jaundice in a man with G6PD deficiency. (Source 15)

• Case report, Very low certainty.
• Size: One patient (single case report)
• Who: A 27-year-old man with glucose-6-phosphate dehydrogenase deficiency admitted with cholecystolithiasis and cholecystitis.
• How long: Single course of ascorbic acid infusion; discharged 11 days later.
• Result: Scleral jaundice and very deep coloured urine after infusion; diagnosis of hemolysis and hyperbilirubinemia induced by ascorbic acid.
• Funding: not stated.

He appeared with scleral jaundice and very deep colored urine after receiving pharmacological doses ascorbic acid infusion.

The US label requires a reduced dose in G6PD deficiency because severe haemolysis has been reported. (Source 11)

• Official position, Certainty not rated.
• Size: Not applicable; regulatory warning text.
• Who: Patients with glucose-6-phosphate dehydrogenase deficiency receiving ascorbic acid.
• How long: Not specified.
• Result: No rate is given; the label says to monitor haemoglobin and blood count, use a reduced dose, and discontinue if haemolysis is suspected.
• Funding: not applicable.

Hemolysis has been reported with administration of ascorbic acid in patients with glucose-6-phosphate dehydrogenase deficiency.

Rapid intravenous administration of ascorbic acid can cause faintness, nausea, lethargy, flushing, dizziness and headache. (Source 16)

• Official position, Certainty not rated.
• Size: Spontaneously reported cases of uncertain denominator.
• Who: Patients given ascorbic acid injection.
• How long: Immediate, during infusion.
• Result: No rates can be estimated; the label states the frequency cannot be reliably estimated. The threshold given is faster than 250 mg/minute, and the most common reactions are pain and swelling at the infusion site.
• Funding: not applicable.

Rapid intravenous administration (> 250 mg/minute) of ascorbic acid injection may cause temporary faintness or nausea, lethargy, flushing, dizziness, and headache

What the evidence supports

Regular vitamin C shortened colds modestly, by 8% in adults and 14% in children. (Source 3)

• Systematic review, Low certainty.
• Size: 9745 cold episodes across thirty-one comparisons.
• Who: Adults and children taking vitamin C regularly.
• How long: Regular daily supplementation.
• Result: Duration of colds reduced by 8% (3% to 12%) in adults and by 14% (7% to 21%) in children; in children 1 to 2 g/day shortened colds by 18%.
• Funding: not stated.

In adults the duration of colds was reduced by 8% (3% to 12%) and in children by 14% (7% to 21%).

A narrative review argues that vitamin C deficiency impairs immunity and puts the intake needed for adequate or saturating blood levels at 100-200 mg a day; this is the review authors' position, not a result measured in a trial. (Source 17)

• Expert review, not systematic, Low certainty.
• Size: Not applicable; expert review with no stated search method.
• Who: Humans generally.
• How long: Not applicable.
• Result: The review states that prophylactic prevention of infection requires intakes giving at least adequate, if not saturating, plasma levels, which it puts at 100-200 mg/day.
• Funding: not stated.

Limit of this finding: This is a narrative review: an expert summary with no stated search method, no pooled numbers and no trial of its own. The 100-200 mg a day figure and the suggestion that gram doses treat established infection are the two authors' reading of the field, not measured outcomes. Their own hedge, that supplementation "appears to be able to" prevent and treat infections, is part of the claim and should not be dropped when it is shortened.

Prophylactic prevention of infection requires dietary vitamin C intakes that provide at least adequate, if not saturating plasma levels (i.e., 100-200 mg/day), which optimize cell and tissue levels.

Scurvy still occurs in high-income countries and presents with bleeding gums, poor wound healing, anaemia and bone pain. (Source 18)

• Case series, Very low certainty.
• Size: eight children in two hospitals, plus a literature review of 126 articles with 253 cases of scurvy.
• Who: Children in Catania, Italy, October 2021 to October 2023, and published cases.
• How long: Two-year case ascertainment window.
• Result: No comparative effect size. Predisposing factors reported were malnutrition and gastrointestinal and neurological disorders.
• Funding: not stated.

Presenting manifestations include malaise, gingival bleeding, impaired wound healing, perifollicular hemorrhage, dry hair and brittle nails, iron deficiency, muscle and joint pain, pulmonary hypertension, and other symptoms.

What the evidence does not support

Regular vitamin C supplementation did not reduce how often people in the general community caught colds. (Source 3)

• Systematic review, Moderate certainty.
• Size: 11,306 participants across twenty-nine trial comparisons; 10,708 in the general community trials.
• Who: General community adults and children, plus a subgroup of marathon runners, skiers and soldiers.
• How long: Varied; regular supplementation over study periods of weeks to months.
• Result: Pooled RR 0.97 (95% CI 0.94 to 1.00) in general community trials; in five trials of 598 marathon runners, skiers and soldiers on subarctic exercises the pooled RR was 0.48 (95% CI 0.35 to 0.64)
• Funding: not stated.

In the general community trials involving 10,708 participants, the pooled RR was 0.97 (95% confidence interval (CI) 0.94 to 1.00).

Vitamin C started after cold symptoms began had no consistent effect on duration or severity. (Source 3)

• Systematic review, Low certainty.
• Size: 3249 cold episodes across seven comparisons.
• Who: People with a cold already under way.
• How long: Therapy begun at symptom onset.
• Result: No consistent effect on duration or severity in the therapeutic trials.
• Funding: not stated.

No consistent effect of vitamin C was seen on the duration or severity of colds in the therapeutic trials.

A 96-hour vitamin C infusion did not improve organ failure scores or inflammatory markers in sepsis with ARDS. (Source 4)

• Randomized trial, Low certainty.
• Size: 167 randomized patients (vitamin C, n = 84; placebo, n = 83)
• Who: Adults with sepsis and ARDS present for less than 24 hours, 7 US medical ICUs.
• How long: 50 mg/kg every 6 hours for 96 hours; biomarkers to 168 hours.
• Result: Modified SOFA change difference -0.10 (95% CI -1.23 to 1.03; P = .86); CRP difference 7.94 mcg/mL (95% CI -8.2 to 24.11; P = .33); thrombomodulin difference 0.69 ng/mL (95% CI -2.8 to 4.2; P = .70)
• Funding: not stated.

There were no significant differences between the vitamin C and placebo groups in the primary end points of change in mean modified Sequential Organ Failure Assessment score from baseline to 96 hours

Adding intravenous vitamin C to hydrocortisone did not shorten vasopressor dependence in septic shock. (Source 19)

• Randomized trial, Moderate certainty.
• Size: 216 patients randomised; 211 completed the primary outcome.
• Who: Adults meeting the Sepsis-3 definition of septic shock in 10 ICUs in Australia, New Zealand and Brazil.
• How long: Until shock resolution or up to 10 days; primary outcome to day 7.
• Result: Time alive and vasopressor free to day 7 was 122.1 hours versus 124.6 hours; median of paired differences -0.6 hours (95% CI -8.3 to 7.2; P = .83). 90-day mortality 30/105 (28.6%) versus 25/102 (24.5%), hazard ratio 1.18 (95% CI 0.69-2.00)
• Funding: not stated.

the median of all paired differences was -0.6 hours (95% CI, -8.3 to 7.2 hours; P = .83). Of 10 prespecified secondary outcomes, 9 showed no statistically significant difference.

High-dose oral vitamin C gave no survival or progression benefit in advanced colorectal cancer. (Source 5)

• Randomized trial, Moderate certainty.
• Size: 100 patients.
• Who: Patients with advanced colorectal cancer in good general condition who had received no previous cytotoxic drugs.
• How long: Not stated in the abstract; outcomes were time to progression and survival.
• Result: No advantage over placebo for interval to disease progression or survival; among patients with measurable disease, none had objective improvement.
• Funding: not stated.

Vitamin C therapy showed no advantage over placebo therapy with regard to either the interval between the beginning of treatment and disease progression or patient survival.

Eight years of 500 mg daily vitamin C did not reduce major cardiovascular events in men. (Source 6)

• Randomized trial, High certainty.
• Size: 14,641 US male physicians; 1245 confirmed major cardiovascular events.
• Who: US male physicians initially aged 50 or older, 5.1% with cardiovascular disease at randomisation.
• How long: Mean follow-up 8 years.
• Result: Vitamin C versus placebo: 10.8 versus 10.9 events per 1000 person-years; HR 0.99 (95% CI 0.89-1.11; P = .91). Total mortality HR 1.07 (95% CI 0.97-1.18; P = .16)
• Funding: not stated.

Limit of this finding: The published JAMA abstract contains a labelling error inside this sentence: the vitamin C event rates, 10.8 and 10.9 events per 1000 person-years, are printed as belonging to the "vitamin E groups". The quote is reproduced exactly as the journal printed it rather than silently corrected. Those two figures are the active and placebo vitamin C arms of the same trial. A reader should not take anything about vitamin E from this sentence; the trial's vitamin E results are the separate sentence before it.

There also was no significant effect of vitamin C on major cardiovascular events (active and placebo vitamin E groups, 10.8 and 10.9 events per 1000 person-years, respectively; HR, 0.99 [95% CI, 0.89-1.11]; P = .91)

Adding vitamin C to oral iron gave no extra haemoglobin or ferritin gain in iron deficiency anaemia. (Source 7)

• Randomized trial, Moderate certainty.
• Size: 440 randomised patients (220 per group); 432 (98.2%) completed.
• Who: Adults with newly diagnosed iron deficiency anaemia in a single-centre, open-label trial at Huashan Hospital, Fudan University; 426 women (96.8%), mean age 38.3 years.
• How long: 3 months of treatment; primary outcome at 2 weeks.
• Result: Haemoglobin change 2.00 g/dL with vitamin C versus 1.84 g/dL without (between-group difference 0.16 g/dL; 95% CI -0.03 to 0.35), meeting the 1 g/dL equivalence margin; ferritin difference 1.27 ng/mL (95% CI -0.70 to 3.24; P = .21); adverse events 46 (20.9%) versus 45 (20.5%)
• Funding: not stated.

Limit of this finding: This was one open-label trial at a single hospital (Huashan Hospital, Fudan University), so patients and staff knew who was getting the vitamin C. "Equivalent" here has a precise, narrow meaning: the difference in haemoglobin fell inside a 1 g/dL margin the investigators set before the trial. It does not show that vitamin C never helps iron absorption in anyone, and the trial was in people already being treated for iron deficiency anaemia.

the mean (SD) change in hemoglobin level was 2.00 (1.08) g/dL in the oral iron supplements plus vitamin C group and 1.84 (0.97) g/dL in the oral iron supplements-only group (between-group difference, 0.16 g/dL; 95% CI, -0.03 to 0.35 g/dL), thus meeting the criteria for equivalence

Where the research disagrees

Whether high-dose intravenous vitamin C helps people with sepsis

• CITRIS-ALI investigators (2019), randomised double-blind placebo-controlled trial, 167 patients: a 96-hour infusion of vitamin C compared with placebo did not significantly improve organ dysfunction scores or alter markers of inflammation and vascular injury (Source 4)
• LOVIT investigators (2022), randomised placebo-controlled trial, 872 patients: those who received intravenous vitamin C had a higher risk of death or persistent organ dysfunction at 28 days than those who received placebo (Source 12)

Whether vitamin C intake raises kidney stone risk

• Ferraro and colleagues (2016), men, prospective cohort analysis of 197,271 people, 6,245 stones: Total and supplemental vitamin C intake was significantly associated with higher risk for incident kidney stones in men, but not in women. (Source 13)
• The same cohort analysis, on diet alone, prospective cohort analysis; observational, not randomised: Dietary vitamin C intake was not associated with stones among men or women, although few participants had dietary intakes > 700mg/d. (Source 13)

How much

• Reference intake: The Recommended Dietary Allowance is set by the Food and Nutrition Board at the National Academies of Sciences, Engineering, and Medicine (the former Institute of Medicine), in its Dietary Reference Intakes report for vitamin C, vitamin E, selenium and carotenoids. As reproduced on the NIH Office of Dietary Supplements fact sheet, it is 90 mg a day for men and 75 mg a day for women aged 19 and over, 85 mg in pregnancy and 120 mg while breastfeeding, and 75 mg for boys and 65 mg for girls aged 14 to 18; people who smoke are said to require 35 mg a day more. The 40 mg and 50 mg infant figures are Adequate Intakes rather than RDAs. Dosing of the prescription ascorbic acid injection is a separate matter and is set by the prescriber; the label's own dose range is recorded under studied doses below. (Source 20)
• Upper limit: The same body sets a Tolerable Upper Intake Level for vitamin C. As reproduced on the NIH Office of Dietary Supplements fact sheet it is 2,000 mg a day for adults aged 19 and over, 1,800 mg for ages 14 to 18, 1,200 mg for ages 9 to 13, 650 mg for ages 4 to 8 and 400 mg for ages 1 to 3, with no level set for infants. This is a ceiling on total daily intake from food and supplements, not a target. The prescription injection carries its own, separate ceiling, recorded under studied doses below. (Source 21)
• Studied: Not a trial dose but what the US label directs: The US label for ascorbic acid injection (effective 2026-09-03) gives 50 mg once daily for infants aged 5 months to under 12 months, 100 mg once daily for ages 1 year to under 11 years, and 200 mg once daily for adults and children 11 years and older, with a maximum recommended duration of one week. The label defers to the US Recommended Dietary Allowance for pregnant women, lactating women and people with G6PD deficiency but does not print the RDA figures. (Source 22)
• Studied: LOVIT gave intravenous vitamin C at 50 mg per kilogram of body weight every 6 hours for up to 96 hours. (Source 12)
• Studied: CITRIS-ALI gave 50 mg/kg in dextrose 5% in water every 6 hours for 96 hours. (Source 4)
• Studied: VITAMINS gave intravenous vitamin C 1.5 g every 6 hours alongside hydrocortisone and thiamine. (Source 19)
• Studied: The advanced cancer trial gave high-dose vitamin C at 10 g daily. (Source 5)
• Studied: The Physicians' Health Study II gave 500 mg of vitamin C daily for a mean of 8 years. (Source 6)
• Studied: The iron deficiency anaemia trial gave 200 mg of vitamin C with each 100-mg oral iron tablet every 8 hours for 3 months. (Source 7)

A common belief, and what the research shows

The belief: Taking vitamin C every day stops you catching colds.

What the research shows: The Cochrane review that pooled twenty-nine trial comparisons in 11,306 participants found a pooled risk ratio of 0.97 (95% CI 0.94 to 1.00) in general community trials, and the authors wrote of "The failure of vitamin C supplementation to reduce the incidence of colds in the general population". Regular supplementation did shorten colds a little (8% in adults, 14% in children), and starting vitamin C after symptoms began showed no consistent effect at all.

Questions and answers

What is it?

Ascorbic acid is vitamin C. It is a water-soluble nutrient that humans cannot make, so it has to come from outside the body. It is also a licensed injectable medicine for scurvy, and the same molecule is sold over the counter as a supplement. (Source 18)

What does it do in the body?

As a medicine its job is to refill the body's vitamin C stores. The US label is candid that exactly how this treats scurvy is unknown. In the body generally, vitamin C donates electrons, acting as an antioxidant and as a cofactor for enzymes that build collagen and regulate genes. (Source 1)

Is it good or bad for you?

Both, depending on amount and setting. Correcting a genuine deficiency is clearly good: scurvy resolves. Large doses are a different matter. The biggest sepsis trial found more death or persistent organ dysfunction on vitamin C than placebo (44.5% versus 38.5%), and prolonged high doses have caused oxalate kidney injury and haemolysis in G6PD deficiency. (Source 12)

How do you get more of it?

From food and from supplements. A narrative review - an expert summary, not a trial - states that keeping blood levels at or near saturation, which it puts at roughly 100-200 mg a day of dietary vitamin C, is what is needed to maintain cell and tissue levels; treating an established infection, it argues, would need gram doses. This is the authors' position on what has been studied, not a recommendation. (Source 17)

If it is harmful, what reduces it?

Vitamin C is water-soluble and cleared by the kidneys, so excess is handled by stopping intake. The label's instruction for overdose is to discontinue administration, treat the symptoms and avoid any further ascorbic acid. Overdose can cause nausea, vomiting, diarrhoea, flushing, rash, headache, fatigue or disturbed sleep. (Source 23)

Why might someone be low in it or missing it?

Mainly because too little is coming in, or because illness is in the way. A case series and literature review of scurvy found malnutrition and gastrointestinal and neurological disorders to be the predisposing factors; in the individual cases, restrictive or picky eating was the common thread. (Source 18)

Which whole foods contain it or feed it?

Fresh fruit and vegetables, with citrus fruit the classic example. The sources reached for this write-up do not contain a food-composition table, so no mg-per-portion figures are given here. The scurvy case series notes that refusing to give children citrus fruits such as lemon and oranges contributed to the cases it found. (Source 18)

What happens if you do not have it?

Prolonged deficiency causes scurvy: malaise, bleeding gums, poor wound healing, bleeding around hair follicles, dry hair and brittle nails, iron deficiency, muscle and joint pain. The case series reports that without treatment the clinical picture worsens severely and progressively. (Source 18)

How can you test for it?

A blood ascorbic acid level is what confirms the diagnosis in practice. In a published paediatric case, scurvy was suspected from the history and radiographs and then confirmed by a low ascorbic acid level. (Source 24)

References

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3. The Cochrane database of systematic reviews. Vitamin C for preventing and treating the common cold.. 2013. PMID 23440782, DOI 10.1002/14651858.cd000980.pub4. Read the source
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10. DailyMed (US National Library of Medicine) / Zydus Pharmaceuticals (USA) Inc.. Ascorbic Acid Injection, for intravenous use - Full Prescribing Information (section quoted below) - section: oxalate [label effective date 2026-09-03]. 2026. Read the source
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15. Medicine. Hemolytic jaundice induced by pharmacological dose ascorbic acid in glucose-6-phosphate dehydrogenase deficiency: A case report.. 2018. PMID 30572463, DOI 10.1097/md.0000000000013588. Read the source
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