One reason health experts encourage us to eat more fruits and vegetables is to get more vitamins and minerals, including vitamin C. Unlike most animals, humans can’t make their own vitamin C and must get it through diet. Some primates, bats, and guinea pigs also must get vitamin C through diet as they’re incapable of making it.
Without enough vitamin C, people develop a vitamin C deficiency disease called scurvy, a serious condition that can lead to death. At one time, people didn’t know that scurvy was due to a vitamin C deficiency. In fact, before the 1800s, millions of sailors and explorers died from scurvy since ships didn’t carry vitamin C-rich foods. These days, we worry less about scurvy since plant-based foods, a good source of the C vitamin, are so widely available.
Scurvy sufferers often have bleeding gums and poor wound healing. In fact, if you’re deficient in vitamin C for a long period, you can lose your teeth and suffer from bleeding gums. That’s because you need vitamin C to maintain the health of connective tissue, specifically the collagen that makes up connective tissue, and to keep your immune system healthy.
Vitamin C is also a powerful antioxidant vitamin that helps prevent oxidative damage to cells and tissues. The recommended daily intake for men is 90 milligrams and for women 75 milligrams, although some experts say we need more. However, consuming megadoses of vitamin C in supplement form can cause digestive upset and increase the risk of kidney stones.
Sources of Vitamin C
Vegetables and fruits are both good sources of vitamin C, although fruit has the edge. Some veggies, like Brussels sprouts are an excellent source of this antioxidant vitamin. However, most people eat their Brussels sprouts cooked. These delicious crucifers may taste delicious roasted or cooked, but cooking destroys a significant amount of vitamin C in vegetables, such as Brussels sprouts. In fact, vitamin C is one of the least stable vitamins. When you expose vitamin C sources of light or heat, you lose some vitamin C.
As a rule, raw fruits and vegetables are better sources of vitamin C than cooked ones, although the cooking method makes a difference. One study found that broccoli lost almost 50% of its vitamin C when exposed to heat. Researchers tested various cooking methods including steaming, boiling, stir-frying, and microwaving. The study found that steaming led to the least loss of vitamin C. Another study found that microwaving broccoli, spinach, and lettuce led to less loss of vitamin C than boiling but steaming preserved vitamin C the best. The study also concluded that all raw vegetables are a better source of vitamin C relative to cooked vegetables.
Vegetables vs. Fruits as a Vitamin C Source
Although vegetables contain substantial amounts of vitamin C, you won’t get the majority of it if you boil them or expose them to high heat for a long period of time. If you always cook your vegetables, include some fruit in your diet to make sure you’re getting enough vitamin C or eat a salad with raw vegetables each day.
Some of the best veggie sources of vitamin C may surprise you. For example, who would think a hot and spicy veggie you get in Mexican restaurants would pack a wallop of vitamin C? In fact, chili peppers top the list with a single green chili pepper supplying 120% of the days recommended daily intake. Red chili peppers have slightly less but they’re also a good source of beta-carotene. Sweet yellow peppers follow close behind with a half cup supplying 150% of the RDA for vitamin C.
Kale is another power source of vitamin C. A cup of raw kale supplies around 90% of the recommended daily intake of vitamin C. However, if you cook it, you lose about 30% of the vitamin C. So, cook your kale lightly or enjoy it raw to maximize the vitamin C content of your diet. Also, add a source of healthy fat to leafy, greens. Doing this will boost the absorption of beta-carotene from the greens since beta-carotene is a fat-soluble nutrient.
Fruits Highest in Vitamin C
Fruit is an excellent source of vitamin C since we don’t, as a rule, cook it. When vitamin C comes to mind, you might think of citrus fruit, like oranges, but there are fruits that contain more vitamin C than an orange. For example, a medium orange contains around 50 milligrams of this antioxidant vitamin. Contrast that with strawberries. These luscious red orbs contain 85 milligrams of vitamin C per serving and kiwi fruit with 70 milligrams in one medium-sized fruit.
Some fruits are an exceptional source of vitamin C, even though they’re harder to find. For example, the camu-camu berry has a sour taste, almost like a Sweet Tart is packed with C. You can buy camu-camu dried powder at some natural food markets and add it to smoothies. One teaspoon delivers 750% of the day’s recommended intake of vitamin C. Rose hips and the acerola cherry are other exceptional sources of vitamin C.
So, look beyond citrus to other vitamin C-packed fruits. Also, buy local when you can. Vitamin C is sensitive to light too. When fruit and vegetables sit on store shelves, they lose their vitamin C. When produce travels too far, losses of vitamin C can be as high as 50%. So, visit your farmer’s market for the best selection of healthy produce.
The Bottom Line
In general, fruit is a better source of vitamin C than vegetables that lose substantial quantities of vitamin C when you cook them. If you’re trying to up the vitamin C content of your diet, add a piece of fruit or two to your diet each day. For example, a serving of strawberries each day supplies enough vitamin C to meet the recommended intake and you get phytonutrients too. Eating a variety of fruit and vegetables will give you the greatest diversity of nutrients, so vary your vitamin C sources.
References:
- National Institutes of Health. “Vitamin C”
- J Zhejiang Univ Sci B. 2009 Aug;10(8):580-8. doi: 10.1631/jzus.B0920051.
- com. “Effects of different cooking methods on the vitamin C content of selected vegetables”
- Self Nutrition Data
- com. “20 Foods That Are High in Vitamin C”
- Medical News Today. “What are the best foods for vitamin C?”
- MedLine Plus. “Vitamin C”
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