Do you need to take vitamin C supplements, and how much is enough? The answer may depend on your age and overall health.

Vitamin C is a water-soluble vitamin with a variety of benefits, but our bodies can’t make it. We need to consume it through the food we eat or by supplementation.

This article explores what vitamin C does, where we can get it, how much vitamin C is the right amount, and who may need to take supplements.

Vitamin C plays a role in many body functions. The immune system is a key one, mainly due to vitamin C’s antioxidant properties.

Antioxidants protect the body from oxidative stress. This is a process that, over time, can cause damage to most organs and tissues in the body. Antioxidants are also known to help support the natural abilities of your immune system.

Although vitamin C is a known antioxidant and has benefits for the immune system, there’s some question over its ability to treat active infections. People often use it as a supplement in the winter months to fight colds, and some even use it as a treatment for COVID-19. However, scientists are yet to prove the true value of these uses.

There is also little scientific data to prove the benefits of vitamin C for chronic conditions that sometimes benefit from antioxidant therapies, such as cancer and cardiovascular disease.

The only condition that vitamin C is proven to help treat is scurvy. Scurvy causes weakness, slow wound healing, bruising, and other symptoms. It’s due to a severe lack of vitamin C in your diet.

In addition to its role as an antioxidant, vitamin C also helps produce or process:

  • collagen, a protein in the body that’s vital for your connective tissues and wound healing
  • L-carnitine, a chemical that helps turn fat into energy
  • neurotransmitters, which help move signals through your nervous system
  • iron that comes from plant-based sources instead of meat

Your body controls the amount of vitamin C in your body very carefully. It’s present in small amounts in most cells. Unlike other forms of vitamins, vitamin C is usually present in higher amounts in cells than in plasma, which is the fluid part of your blood.

Daily vitamin C intake is recommended at every age, but this doesn’t necessarily mean that you need to take supplements.

How much vitamin C you need every day depends on your age and how much you take in through your diet. According to the National Institutes of Health, your body will absorb 70–90% of the vitamin C you consume if you take in a moderate amount. The NIH considers 30–180 milligrams (mg) per day to be a moderate amount.

If you take in more than 1 gram of vitamin C in a day, your body will absorb less than half of it and get rid of the rest in your urine.

This makes it important to know how much you need for your age each day to avoid taking supplements that your body wouldn’t absorb anyway. By age, vitamin C intake recommendations — per the NIH — are:

  • babies and infants: 40–50 mg per day
  • children ages 1–8: 15–25 mg per day
  • children ages 9–13: 45 mg per day
  • teens ages 14–18: 65–75 mg per day
  • adults: 75–90 mg per day

In general, males need higher amounts within these ranges, and those who are pregnant or breastfeeding need more vitamin C as well.

Talk with your healthcare team or obstetrician before taking any supplements while pregnant or breastfeeding.

If you smoke, your vitamin C requirements are also higher. The NIH recommends an additional 35 mg per day of vitamin C for people who smoke cigarettes.

Many foods contain vitamin C, and you can usually get the recommended daily amount of vitamin C from the foods you eat if you consume a balanced diet.

In most cases, getting vitamins and minerals from the food you eat is better than taking supplements. And if you already get enough vitamin C in your diet, your body won’t use much of what extra you take in, anyway.

Most vitamins are suitable to take at any time of the day, but you may want to check with your doctor before starting any supplements.

Certain vitamins and minerals, including vitamin C, can interact with some prescription medications. If you choose to take a vitamin C supplement, you may need to coordinate the timing of the supplement with the timing of any other medications you take.

Examples of medications that could interact with vitamin C include:

You may also need to watch your vitamin C intake if you have conditions like kidney stones or if you get hemodialysis.

Some foods high in vitamin C include:

  • citrus fruits
  • red and green peppers
  • kiwi
  • broccoli
  • strawberries
  • canteloupe
  • baked potatoes
  • tomatoes

Other foods contain vitamin C added during the manufacturing process, such as certain varieties of milk and cereals.

Depending on how much of these foods you eat, you may get enough vitamin C in your diet without realizing it. For example, a single orange contains about 83 mg of vitamin C, and a cup of sliced strawberries contains about 98 mg.

Too little vitamin C can cause symptoms of deficiency, including:

Scurvy is the most severe form of vitamin C deficiency, and it can be fatal without treatment.

If you get more vitamin C than you need, your body will usually get rid of it through your urine. However, excessively high amounts can also be dangerous.

Some symptoms that indicate you’re taking in too much vitamin C include:

For this reason, the NIH says adults should consume no more than 2,000 mg of vitamin C per day. This includes vitamin C from foods and supplements combined.

Vitamin C plays an important role in many processes in our bodies. Many people get enough vitamin C from their diet alone, but supplements can help those whose diets are lacking certain types of foods.

Some people may take supplements as a way to help treat certain conditions, but evidence that vitamin C can help fight a cold or treat chronic conditions is lacking.

Talk with your healthcare team before starting any nutrition supplements if you take prescription medications or have a chronic condition. Some supplements can interact with medications or cause complications for certain therapies.