What is vitamin C in?: Your Guide to Optimal Food Sources

October 26, 2025 •

4 min read

Unlike most mammals, humans cannot produce their own vitamin C and must obtain it from dietary sources. If you're asking 'what is vitamin C in?', the answer is a diverse array of fresh, whole foods, with some surprising options packing an even bigger punch than the classic orange.

Quick Summary

This article explores the wide variety of food sources for vitamin C, detailing which fruits and vegetables offer the highest concentrations. It covers the importance of this essential nutrient for overall health and provides practical tips for maximizing its benefits through your diet.

Key Points

Diverse Sources: While citrus is popular, some of the highest concentrations of vitamin C are found in foods like Kakadu plums, acerola cherries, and bell peppers.
Veggies are Key: Many vegetables, including broccoli, kale, and Brussels sprouts, are excellent sources of vitamin C, providing substantial amounts alongside other nutrients.
Preparation Matters: Heat, water, and prolonged storage can significantly reduce vitamin C content in foods. Eating raw or lightly steaming helps preserve the vitamin.
Antioxidant Power: Vitamin C functions as a powerful antioxidant, protecting your cells from damage caused by free radicals and supporting a healthy immune system.
Collagen and Iron: It is crucial for collagen production, vital for healthy skin and tissues, and enhances the absorption of non-heme iron from plant-based foods.
Daily Intake: Because the body cannot produce or store vitamin C, it must be consumed regularly through a varied diet of fruits and vegetables.

Understanding the Importance of Vitamin C

Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that plays a crucial role in numerous bodily functions. It acts as a powerful antioxidant, protecting cells from damage caused by free radicals generated during normal metabolic processes or from exposure to pollutants and toxins. This cellular protection is vital for reducing inflammation and the risk of chronic diseases like cardiovascular issues and certain cancers.

Beyond its antioxidant properties, vitamin C is essential for the production of collagen, a protein that provides structure to skin, tendons, ligaments, and blood vessels. This makes it indispensable for wound healing, maintaining healthy connective tissues, and supporting a youthful appearance. Additionally, vitamin C significantly enhances the absorption of non-heme iron, the type of iron found in plant-based foods. A strong immune system also relies heavily on adequate vitamin C, as it supports the function of various immune cells that fight off infections.

Since the human body cannot produce or store this vital nutrient, a consistent daily intake from food is necessary to prevent deficiency.

Top Fruit Sources for Vitamin C

While oranges are famously known for their vitamin C content, many other fruits contain even higher concentrations. Incorporating a variety of these into your daily diet can help ensure you meet your nutritional needs. Eating them raw is often the best way to preserve their vitamin C, as heat can degrade it.

Kakadu Plums: This Australian native fruit is by far the richest known source of vitamin C, containing up to 100 times more than an orange.
Acerola Cherries: Just half a cup of these tart cherries can provide a massive dose of vitamin C, far exceeding the daily recommended value.
Guavas: A single guava contains more vitamin C than an entire medium-sized orange.
Blackcurrants: These dark berries are loaded with vitamin C and other antioxidants known as anthocyanins.
Strawberries: A single cup of sliced strawberries provides a full day's requirement of vitamin C for most adults.
Kiwifruit: A single medium kiwi fruit is packed with over half of the daily value for vitamin C.
Citrus Fruits: Oranges, grapefruits, and lemons remain excellent and widely available sources of vitamin C.

High-Content Vegetable Sources

Vegetables offer a powerful and often underestimated source of vitamin C. Bell peppers are a standout example, but many cruciferous and leafy greens are also excellent choices.

Chili Peppers: Both green and red chili peppers are exceptionally high in vitamin C.
Sweet Yellow Peppers: The vitamin C content in bell peppers increases as they mature, with yellow varieties offering a substantial amount.
Mustard Spinach: A cup of this raw leafy green provides an abundance of vitamin C, easily covering your daily needs.
Kale: This cruciferous vegetable is highly nutritious and contains significant vitamin C, whether eaten raw or cooked.
Broccoli: A reliable source, broccoli offers a good amount of vitamin C, especially when steamed or microwaved to preserve the nutrients.
Brussels Sprouts: Like broccoli, Brussels sprouts are a great source of vitamin C and other beneficial vitamins.
Cauliflower: Raw cauliflower contains a decent amount of vitamin C, making it a healthy addition to your diet.
White Potatoes: A single baked potato contains a moderate amount of vitamin C, contributing to your daily intake.

The Role of Food Preparation in Preserving Vitamin C

Vitamin C is water-soluble and sensitive to heat, light, and air, so proper food preparation is key to preserving its nutritional value. Raw or lightly cooked fruits and vegetables will retain the highest levels of the vitamin. Steaming or microwaving, which use less water and shorter cooking times, are preferable to boiling, where the vitamin C can leach into the discarded water. Additionally, storing fruits and vegetables correctly, away from direct sunlight, helps maintain their vitamin C content.

Maximizing Your Vitamin C Intake: A Comparison

To help visualize the difference in vitamin C content between various foods, here is a comparison table showing the approximate amount of vitamin C in some popular sources per 100g serving.


Food Source	Vitamin C (mg) per 100g	Notes
Kakadu Plum	1000–5300	The richest known source.
Acerola Cherry	1677	Exceptionally high content.
Guava	228	A great tropical source.
Sweet Yellow Pepper	183	Content increases with ripeness.
Orange	53	A reliable, popular choice.
Broccoli, Raw	81.2	Higher than cooked version.
Strawberries	97.6	A flavorful and abundant source.
Potato, Raw	72.7	Significant amount for a common food.

Conclusion

Answering the question 'what is vitamin C in?' reveals a vibrant and varied world of food. While citrus fruits are a good and familiar starting point, the true powerhouses of vitamin C are found in a wide range of lesser-known and common fruits and vegetables, including bell peppers, guavas, and berries. By incorporating a diverse selection of raw or lightly cooked produce into your diet, you can easily meet your daily needs and reap the immense benefits of this essential antioxidant. Remember that a balanced and colorful diet is the most effective way to maintain optimal vitamin C levels and support your overall health. A balanced diet rich in fruits and vegetables can provide more than enough vitamin C to prevent deficiencies and support a healthy immune system, collagen formation, and iron absorption.

For more detailed information on nutrient content and dietary guidelines, consulting authoritative sources like the National Institutes of Health is recommended.

Frequently Asked Questions

The Kakadu plum, an Australian native, has the highest known concentration of vitamin C in any food. Other excellent fruit sources include acerola cherries, guavas, and blackcurrants.

Yes, many vegetables are excellent sources of vitamin C. Sweet yellow and red bell peppers, chili peppers, kale, and mustard spinach are all exceptionally high in this nutrient.

Yes, vitamin C is sensitive to heat, light, and oxygen. Boiling can cause significant loss as the vitamin leaches into the water. To minimize loss, opt for raw consumption, or quick cooking methods like steaming or microwaving.

Vitamin C helps the body absorb non-heme iron, the type found in plant-based foods. Including a vitamin-C-rich food with a meal containing non-heme iron can significantly increase its absorption.

Vitamin C is essential for collagen production, the protein responsible for skin elasticity and structure. This helps with wound healing and maintaining healthy, youthful-looking skin.

While supplements can provide vitamin C, experts generally recommend getting your nutrients from a balanced diet rich in whole foods. Foods offer a wider range of vitamins, minerals, and other beneficial compounds.

Because vitamin C is water-soluble, excess amounts are typically flushed out by the body. However, amounts exceeding 2,000 mg per day can cause gastrointestinal discomfort like diarrhea in some individuals.