You got your blood test back and vitamin C isn't on it. Almost nobody's is. Yet you're tired, you bruise if you look at a table corner, cuts take ages to close, and a clinic down the road is offering a "high-dose vitamin C infusion" for the price of a nice dinner.
This article explains what a low vitamin C level actually looks like, why it hides inside other markers you do have, why the drip is mostly marketing, and what to eat to fix it in a couple of weeks.
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. If you have symptoms you're concerned about, consult your doctor.
What Is Vitamin C?
Vitamin C (ascorbic acid) is a water-soluble vitamin your body can't make or store in any real quantity. You need a steady supply from food, and what you don't use is gone in your urine within hours.
Think of it as the site foreman for your body's repair work. It's needed to build collagen, the scaffolding in skin, blood vessels, gums, tendons and bone. It helps you absorb iron from plant foods. It mops up oxidative damage. And it's used up faster when you're stressed, ill, smoking or fighting inflammation. When the foreman goes missing, repairs stall everywhere at once: gums, skin, healing, energy.
What Do the Numbers Mean?
If vitamin C is measured, it's usually as plasma ascorbate, reported in µmol/L or mg/dL. Reference ranges vary between labs, so check the one printed on your report.
| Level | Plasma vitamin C | What it means |
|---|---|---|
| Deficient | < 11 µmol/L (< 0.2 mg/dL) | Scurvy territory; bleeding gums, bruising, fatigue likely |
| Low / marginal | 11–28 µmol/L (0.2–0.5 mg/dL) | Symptoms often present but vague; common in smokers and low fruit-and-veg diets |
| Adequate | 28–70 µmol/L (0.5–1.2 mg/dL) | Normal function |
| Saturated | > 70 µmol/L (> 1.2 mg/dL) | The most your body will hold; extra is excreted |
Not sure where your number falls? Enter it here and get the reading in plain words. Vitamin C is rarely measured, so start with ferritin, the marker it's most closely tied to.
Lab "normal" vs how you feel. Most people with vague vitamin C symptoms sit in the "low" band, not the deficient one. Outright scurvy is rare in Europe. Marginal status is not: surveys put it at roughly one adult in ten, higher among smokers and people on restrictive diets. Nobody gets a diagnosis at 20 µmol/L, but plenty feel it.
Vitamin C and Your Other Markers
Because vitamin C is so rarely tested, the practical question is: which numbers on the panel you do have hint at it?
- Ferritin and iron. Vitamin C converts plant (non-haem) iron into the form your gut can absorb. Low vitamin C and low ferritin travel together, especially on vegetarian or low-fruit diets. If your ferritin is low and you're eating iron-rich plants without much fruit or vegetables, vitamin C is a likely missing link. Check your ferritin here, and read our full low ferritin guide.
- CRP. Inflammation burns through vitamin C. A raised CRP with a low fruit-and-veg diet is a fair bet for marginal status, and the vitamin is one of the nutrients that helps bring CRP down.
- Slow healing and gum bleeding. Not a blood marker, but the most specific sign there is. If your dentist comments on your gums and you bruise easily, that's collagen repair struggling.
- Haemoglobin. Chronic low vitamin C can contribute to a mild anaemia through poor iron absorption and, in severe cases, small bleeds.
None of these prove low vitamin C. Together, with a diet light on fresh produce, they make it likely enough to act on. And acting on it costs a bag of peppers.
Symptoms of Low Vitamin C
Marginal deficiency creeps in over weeks:
- Fatigue and irritability, often the first sign, and the one nobody links to a vitamin
- Bruising easily, small purple marks you don't remember earning
- Bleeding or swollen gums, particularly when brushing
- Slow wound healing, cuts that reopen or stay red for weeks
- Rough, dry skin with tiny red dots around hair follicles
- Corkscrew-shaped body hairs, an odd but specific sign
- Aching joints and muscles, from weakened connective tissue
- Low mood, vitamin C is involved in making noradrenaline
- Frequent minor infections, or infections that linger
Why Vitamin C Runs Low
- Simply not eating enough fruit and vegetables. The most common reason by far. Coffee, toast, a sandwich, pasta, repeat. It's a normal European week and it contains almost no vitamin C.
- Smoking. Smokers need about 35 mg more per day and typically have lower blood levels.
- Restrictive diets. Carnivore, very low-carb, or "beige" eating during stress or low mood.
- Heavy cooking. Vitamin C is destroyed by heat and leaches into water. Long-boiled vegetables lose half or more.
- Alcohol. Reduces absorption and increases loss.
- Chronic inflammation or illness. Higher turnover means higher need.
- Gut conditions. Coeliac disease, inflammatory bowel disease and bariatric surgery reduce absorption.
Why IV Vitamin C Is Mostly Marketing
The pitch is that an infusion "bypasses the gut" and delivers what food can't. Here's what actually happens.
Your gut is excellent at absorbing vitamin C. Up to about 200 mg a day, absorption is 70–90%. Two kiwis and a pepper get you there. The system is designed to be filled from food.
Your kidneys set the ceiling. Blood levels plateau around 70–80 µmol/L no matter how much you take in, because the kidneys filter out the rest. An infusion pushes levels far above that for a few hours, and then the surplus leaves in your urine, along with the fee. By the next morning, you're back where diet put you.
Tissue stores fill from ordinary intake. White blood cells and other tissues saturate at a daily intake of roughly 100–200 mg. There is no evidence that briefly flooding the blood does anything more for fatigue or immunity in someone who isn't severely deficient.
Where infusions have a place: people who genuinely cannot absorb through the gut, some hospital settings, and specific research contexts. That's a medical decision. For tiredness and a lacklustre diet, the food version works and it lasts.
None of this is a criticism of anyone who has tried a drip. It's just that the same money buys several weeks of berries, peppers and citrus, and those keep working.
What to Eat to Raise Vitamin C
The EU reference intake is 95 mg a day for women and 110 mg for men, with more for smokers. Reaching 150–200 mg from food is easy once you know where it hides, and it isn't only citrus.
Top Food Sources
| Food | Vitamin C per 100 g | Raw or cooked |
|---|---|---|
| Yellow / red pepper | 130–180 mg | Raw; roughly 100 mg after brief roasting |
| Blackcurrants | 180 mg | Raw or frozen; frozen keeps most of it |
| Parsley | 130 mg | Raw; a generous handful adds 15–20 mg |
| Kiwi | 90 mg | Raw; one fruit is about 60 mg |
| Broccoli | 90 mg raw, 65 mg steamed | Steam 3–4 minutes, don't boil |
| Brussels sprouts | 85 mg raw, 60 mg cooked | Same rule |
| Strawberries | 60 mg | Raw |
| Orange | 55 mg | Raw; one medium orange is about 70 mg |
| Kale | 90 mg raw, 40 mg cooked | Raw in salads, or lightly wilted |
| Sauerkraut (raw, unpasteurised) | 15–20 mg | Modest amount, but it survives storage all winter |
| Potatoes | 15–20 mg | Cooked; low per 100 g but eaten in quantity |
Two practical points. First, vitamin C content drops with storage, so a pepper eaten this week beats one eaten in three weeks. Second, frozen berries and vegetables are frozen within hours of picking and often contain more vitamin C than "fresh" produce that's travelled for a week.
Country-Specific Meal Ideas
Germany / Austria: Paprika sticks with Quark dip, rohes Sauerkraut on the side of a warm meal, Johannisbeeren (blackcurrants) on Müsli, Kartoffelsalat with plenty of parsley
Netherlands / Belgium: Spruitjes lightly steamed with lemon, paprika and komkommer with lunch, kiwi at breakfast, boerenkool served raw-ish rather than stamped to death
France / Switzerland: Salade de chou rouge, cassis on yoghurt, persillade on everything, oranges and clementines in season
Spain / Italy: Pimientos asados (briefly roasted, not stewed), naranjas, gazpacho (raw peppers and tomatoes), broccoli ripassati cooked quickly, fragole
Sweden / Finland / Norway: Svarta vinbär and hjortron (cloudberries) on porridge, rå broccoli in salads, paprika with knäckebröd, potatoes with dill and parsley, rosehip soup (nyponsoppa)
What Blocks and What Helps
What destroys vitamin C before you eat it
- Boiling. Up to half the vitamin C ends up in the water. Steam, stir-fry or eat raw.
- Long storage. Cut fruit and vegetables lose vitamin C to air. Buy little and often, or use frozen.
- Keeping cooked vegetables warm. A hotplate at a buffet is a vitamin C incinerator.
- Baking soda in cooking water. An old trick for green colour that wipes out the vitamin.
What helps
- Eat something raw at every meal. Half a pepper, a kiwi, a handful of berries. Small, frequent doses beat one big one, because you can only absorb so much at once.
- Pair vitamin C with plant iron. Lentils with tomatoes, spinach with lemon, beans with peppers. This is the cheapest ferritin intervention there is.
- Add citrus or parsley at the end of cooking, not the start.
- Frozen is fine. Often better than fresh for berries and broccoli.
A 7-Day Meal Plan for Low Vitamin C
Day 1
- Breakfast: Porridge with frozen blackcurrants and a kiwi
- Lunch: Lentil salad with roasted red pepper, tomato and parsley
- Dinner: Chicken with steamed broccoli and new potatoes with lemon
Day 2
- Breakfast: Yoghurt with strawberries and orange segments
- Lunch: Gazpacho with wholegrain bread
- Dinner: Bean chilli with raw pepper strips and lime
Day 3
- Breakfast: Rye bread with cottage cheese and sliced yellow pepper
- Lunch: Kale and orange salad with walnuts
- Dinner: Salmon with lightly steamed Brussels sprouts and potatoes
Day 4
- Breakfast: Smoothie with frozen berries, kiwi and spinach
- Lunch: Tabbouleh (heavy on parsley) with chickpeas
- Dinner: Stir-fried tofu with broccoli, pepper and mangetout
Day 5
- Breakfast: Overnight oats with grated apple and blackcurrants
- Lunch: Sandwich with hummus, red pepper and rocket; a clementine
- Dinner: Beef and vegetable stir-fry with peppers and a squeeze of lime
Day 6
- Breakfast: Eggs with wilted spinach and tomato; orange juice (a small glass)
- Lunch: Potato salad with plenty of parsley and a side of raw sauerkraut
- Dinner: Roast cod with pimientos asados and a green salad
Day 7
- Breakfast: Yoghurt with kiwi, strawberries and seeds
- Lunch: Red cabbage slaw with apple and a lentil soup
- Dinner: Chicken and pepper skewers with tabbouleh
How Long Will It Take?
Vitamin C is one of the fastest deficiencies to correct, because there's no long supply chain to rebuild.
| Starting point | What to expect | Timeframe |
|---|---|---|
| Deficient (< 11 µmol/L), with gum bleeding or bruising | Blood levels rise within days; gums and bruising improve | 1–2 weeks for symptoms, 4 weeks to full recovery |
| Low / marginal (11–28 µmol/L) | Energy and healing improve gradually | 2–4 weeks of 150–200 mg daily from food |
| Low ferritin alongside | Iron absorption improves immediately; ferritin itself moves slowly | 8–12 weeks, then retest ferritin |
If symptoms haven't shifted after four weeks of eating this way, something else is going on, and that's a conversation with your doctor rather than more oranges.
Should You Supplement?
For most people, no. Food covers it within days and comes with fibre, folate and potassium attached. A plain 100–200 mg tablet is a reasonable bridge if you can't eat fruit and vegetables for a while (illness, travel, a very restricted diet), and it's cheap. Doses above 1,000 mg a day mostly produce expensive urine and, in some people, loose stools and a higher risk of kidney stones. Anything intravenous is a decision for your doctor, not a wellness menu.
Frequently Asked Questions
Can you get too much vitamin C from food?
Realistically, no. Absorption drops as intake rises, and the kidneys excrete the excess within hours. You'd need to eat several kilograms of peppers to approach the amounts that cause problems, and by then the fibre would have stopped you. The upper limit concerns (kidney stones, digestive upset) apply to high-dose supplements above about 1,000 mg a day, not to a fruit bowl.
Does cooking destroy vitamin C?
Partly. Boiling is the worst: up to half leaches into the water, more if you cook for long. Steaming for three to four minutes keeps around 70–80%. Stir-frying briefly keeps most of it. Microwaving with very little water is surprisingly good. The simplest fix is to eat something raw at each meal and add citrus or parsley after cooking rather than before.
Do I need an IV drip if I'm exhausted?
Almost certainly not. Fatigue has many causes, and low ferritin, low vitamin D, low B12 and thyroid issues are all far more common than vitamin C deficiency in Europe. An infusion raises blood vitamin C for a few hours and then the surplus is excreted. If your diet is low in fruit and vegetables, two weeks of eating 150–200 mg a day from food achieves the same tissue levels and keeps them there. If you're still exhausted after that, get your ferritin, B12, vitamin D and thyroid checked.
Which blood markers show vitamin C status indirectly?
Low ferritin is the most useful clue, because vitamin C drives absorption of plant iron. A raised CRP suggests higher turnover of the vitamin. Slightly low haemoglobin with normal B12 and folate can fit too. None of these is proof, but combined with easy bruising, bleeding gums and a diet light on fresh produce, they make marginal vitamin C status likely enough to fix through food and see what changes.
The Bottom Line
Vitamin C is rarely on your blood test, but its shortage shows up in your ferritin, your gums, your bruises and your energy. The fix is not a drip; it's peppers, kiwi, berries, broccoli and parsley, eaten raw or barely cooked, a little at every meal. Levels rise within days and symptoms within weeks. If you have a low ferritin result too, this is the cheapest lever you can pull.
Want to know why we start from a standard blood panel rather than a gut-microbiome kit? Read our comparison with ZOE and similar programmes.
Have your ferritin number? Enter it at chemyou.ai and see what it means for your energy in 30 seconds. No PDF needed. If you have the full lab report, you can upload it there too.