Which food comes to mind first when you think of vitamin C? Lemons? Oranges? Tangerines?Although all citrus fruits are good sources of the essential micronutrient, they actually sit somewhere in the middle of the list. “People don’t realize that vegetables contain more vitamin C,” says Dr. Anne Gürtler. “First and foremost: bell peppers. Just one covers an adult’s average daily requirement of an adult. Broccoli, Brussels sprouts, and kale are also particularly rich in vitamin C.”

How much vitamin C does the body need?

Just as most people think oranges are the way, many people think they need more vitamin C than they do. “It’s often overestimated,” says Gürtler, pointing out that the general recommendation is 100 mg per day, with women needing a little less than men unless they’re pregnant or breastfeeding. Smokers of all sexes, however, could use a little extra: “Because they have such high oxidative stress due to nicotine, you can add another 40-50 mg per day on top,” says Gürtler.

For those wondering exactly how much 100 mg of vitamin C is, one cup of chopped red bell pepper contains around 200 mg; one cup of strawberries, around 98 mg.

What does vitamin C do?

Vitamin C is an antioxidant. “This means that it neutralizes free radicals in the body, protecting the cells from damage and counteracting inflammatory processes and premature skin aging,” says Gürtler. “In addition, vitamin C is essential for cell proliferation and cell differentiation—processes that are also central to the health and regeneration of the skin.”

Recent studies in cancer biology also indicate that vitamin C has modulating properties. “It can act on enzymes that play a crucial role in gene expression,” adds Anne Gürtler.

In relation to the skin, vitamin C is relevant on several levels. “It is a key factor for the differentiation and function of the cells and therefore, for the structure, elasticity and regenerative capacity of the skin—both for the cells of the epidermis, the keratinocytes, and for the collagen-forming fibroblasts in the dermis.”

Are vitamin C supplements worth it?

The body cannot produce vitamin C by itself. Consuming it is the only way to make sure we get enough: “It is absorbed via receptors in the small intestine,” explains Gürtler. “However, these receptors only have a limited absorption capacity.”

This means that above a certain amount, the body can no longer absorb vitamin C. “Above 200 milligrams per day, absorption barely increases. Even if you consume more vitamin C, your body won’t benefit. This shows that excessive intake—for example via high-dose supplements—generally has little additional benefit,” says Gürtler.

What happens if you overdose on vitamin C?

Is it dangerous to consume too much vitamin C? Not really. “A genuine overdose of vitamin C is unlikely,” says Gürtler. “It’s water-soluble and the body cannot store excess amounts; the excess is just excreted via the kidneys.”

That said, it is worth mentioning that very high doses of vitamin C—especially in the form of supplements—can cause side effects. These include gastrointestinal issues like diarrhea, gas, or abdominal cramps. In cases in which someone takes a consistently high amount over long periods of time, vitamin C can also increase the likelihood of kidney stones, especially in those who are already susceptible to them.

In other words, more vitamin C is not always better. The body only absorbs what it can use; the rest is eliminated. “A balanced diet is enough to cover most people’s needs without any problems,” says Gürtler.

What to eat for vitamin C

As a general rule, raw fruits and vegetables contain the most vitamin C. “Because vitamin C is sensitive to heat, vegetables should only be cooked gently, if at all,” explains Gürtler. She says frozen vegetables are also an option: “They have a bad reputation, and wrongly so. They are usually processed and frozen straight after harvesting, which often preserves the vitamin C content even better than fresh vegetables that have been stored or transported for a long time.”

Another simple way to increase your vitamin C intake? Lemon water. “Even though citrus fruits are not the most vitamin C-rich food, their contribution should not be underestimated,” Gürtler, who names water with lemon as her personal go-to drink. Just be mindful of your teeth—the acid can have a corrosive effect on their enamel.

What are the benefits of vitamin C in skin care?

We all know vitamin C can be great for the skin. “It supports collagen synthesis, promotes cell differentiation, and can even out skin tone. It also slows down melanin synthesis, which is why it can be useful for pigmentation irregularities,” explains Gürtler, who recommends using a vitamin C serum in the morning. “Throughout the day, the skin is exposed to oxidative stress; vitamin C can have a preventative effect.”

However, as an antioxidant, vitamin C oxidizes very quickly. Contact with oxygen, UV radiation, or heat can reduce its effect. “That’s why most vitamin C supplements come in dark bottles,” notes Gürtler, who advises buying small bottles. “The more often you open the product, the more the effect are lost.”

Preparations that contain additional ingredients such as vitamin E or ferulic acid also make sense. “This combination protects vitamin C from oxidizing too quickly and ensures that it remains effective for longer,” says Gürtler. She does advise caution when it comes to using highly concentrated products: “They can sting and irritate the skin. Less and more regularly is the better way to go.”

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