Most adults need 75 to 90 mg of vitamin C per day. Women should aim for 75 mg, and men should aim for 90 mg. That’s easily achievable through diet alone: a single medium orange delivers 83 mg, and a cup of sliced strawberries provides 97 mg. But the right number shifts depending on your age, sex, and a few lifestyle factors worth knowing about.
Daily Recommendations by Age and Sex
The recommended daily allowance (RDA) increases as you age, reflecting the body’s growing needs through development and adulthood:
- Children 1 to 3 years: 15 mg
- Children 4 to 8 years: 25 mg
- Children 9 to 13 years: 45 mg
- Teen girls 14 to 18: 65 mg
- Teen boys 14 to 18: 75 mg
- Adult women 19+: 75 mg
- Adult men 19+: 90 mg
- Pregnant women: 85 mg
- Breastfeeding women: 120 mg
Smokers need an extra 35 mg per day on top of the standard recommendation. Smoking increases oxidative stress and depletes the body’s vitamin C stores faster, so a male smoker, for instance, should target about 125 mg daily.
Why 10 mg Prevents Scurvy but Isn’t Enough
Scurvy, the classic vitamin C deficiency disease, can technically be prevented with just 10 mg a day. That was the conclusion of a landmark study conducted by researchers at Sorby Research Institute decades ago. But a more recent reanalysis of that same trial data, published by University of Washington researchers in 2021, found the bar is much higher for full health. An average daily intake of 95 mg is needed to prevent weakened wound healing in 97.5% of the population.
That gap between “enough to avoid scurvy” and “enough for your tissues to function well” is why modern RDAs land in the 75 to 90 mg range rather than at a bare minimum. The goal isn’t just avoiding deficiency. It’s maintaining the vitamin C levels your body needs for everyday repair and protection.
What Vitamin C Actually Does in Your Body
Vitamin C plays two major roles. First, it’s essential for producing collagen, the structural protein that holds your skin, tendons, blood vessels, and bones together. Without adequate vitamin C, the collagen your body makes is unstable and can’t properly support tissue. This is why deficiency shows up as slow wound healing, bleeding gums, and skin that bruises easily. Vitamin C also stabilizes collagen at the genetic level, increasing how much collagen protein your cells produce for tissue repair.
Second, it works as an antioxidant, neutralizing the unstable molecules (free radicals) that damage cells. In skin specifically, vitamin C is found at high concentrations in both the outer and deeper layers, where it limits damage from ultraviolet light exposure. It reduces UV-related DNA damage, lowers inflammation, and helps skin cells survive sun exposure. Vitamin C also boosts the activity of immune cells, though the degree to which extra supplementation beyond the RDA improves immune function in healthy, well-nourished people is less clear-cut than supplement marketing suggests.
Your Body Stops Absorbing Efficiently Above 200 mg
One of the most practical things to know about vitamin C is how your intestines handle it. Your body absorbs 100% of a dose up to 200 mg. Once you go above 500 mg in a single dose, absorption drops significantly, and the excess passes through your digestive tract unabsorbed. This is worth keeping in mind if you take supplements: a 1,000 mg tablet doesn’t deliver five times the benefit of a 200 mg dose. Your body simply can’t use most of it.
If you do want to supplement above the RDA, splitting doses into smaller amounts taken throughout the day will give you better absorption than one large dose. But for most people eating a reasonably varied diet, supplementation isn’t necessary at all.
Food Sources That Cover Your Needs
Fruits and vegetables are the most efficient way to hit your daily target, and you don’t need exotic superfoods to get there. One large yellow bell pepper packs a remarkable 342 mg of vitamin C, nearly four times the daily value. A cup of sliced strawberries provides 97 mg. A single medium orange gives you 83 mg. Even half a cup of raw broccoli or a medium kiwi gets you well past the halfway mark.
Because vitamin C is water-soluble and sensitive to heat, raw or lightly cooked produce delivers more than heavily boiled vegetables. That said, most people who eat a few servings of fruits and vegetables daily are getting enough without thinking about it.
The Upper Limit and Side Effects
The tolerable upper intake level for adults is 2,000 mg per day. Going above that regularly increases the risk of digestive problems: diarrhea, nausea, and abdominal cramps. These happen because unabsorbed vitamin C draws water into the intestines, creating an osmotic effect that loosens stool. Even at doses below 2,000 mg, some people experience stomach discomfort, particularly on an empty stomach.
There’s also a kidney stone concern. Vitamin C is partly metabolized into oxalate, and high-dose supplements have been linked to an increased risk of calcium oxalate kidney stones, particularly in men. If you have a history of kidney stones, high-dose vitamin C supplements are worth avoiding. For the general population, staying at or near the RDA through food carries no known risks.
Who Might Need More Than the RDA
Beyond smokers, a few other groups tend to have lower vitamin C levels. People regularly exposed to secondhand smoke face similar oxidative stress as smokers and benefit from higher intake. Those with limited dietary variety, whether due to food access, restrictive diets, or certain digestive conditions that reduce absorption, are also at greater risk of running low.
Alcohol use in heavy amounts can impair vitamin C absorption and increase excretion. And older adults who eat less overall sometimes fall short simply because their total food intake has declined. For these groups, a modest supplement in the 100 to 200 mg range fills the gap efficiently, right in the sweet spot where your body absorbs nearly all of it.