Does the Sun Give You Vitamin C? The Surprising Truth Revealed

January 12, 2026 •

3 min read

An estimated 24% of adults in the UK do not get enough vitamin C from their diet alone, which has led to many myths about where we can obtain this essential nutrient. One common misconception is that sun exposure can boost your vitamin C levels, similar to how it helps with vitamin D synthesis. The truth, however, is quite different and is rooted in how our bodies process these distinct vitamins.

Quick Summary

Sunlight does not provide vitamin C, which must be obtained from food or supplements because the human body cannot produce it. This contrasts with vitamin D, which our skin synthesizes when exposed to sunlight.

Key Points

Sunlight does not provide vitamin C: The sun's UV rays trigger the body to produce vitamin D, not vitamin C, which is a common misconception.
Humans cannot synthesize vitamin C: Unlike most animals, our bodies lack the necessary enzyme to produce vitamin C, making us entirely dependent on external sources.
Dietary intake is the only source of vitamin C: This essential nutrient must be consumed through a diet rich in fruits, vegetables, or through supplementation.
Vitamin C is a water-soluble antioxidant: It supports immune function, collagen synthesis, and wound healing, whereas vitamin D is a fat-soluble hormone for bone health.
Rich food sources include citrus fruits and bell peppers: Excellent dietary sources of vitamin C extend beyond oranges to include kiwi, strawberries, broccoli, and red peppers.
Vitamin C is sensitive to heat and light: The nutrient content in foods can decrease with cooking and prolonged storage, so fresh, raw options are best.
Excess vitamin C is typically excreted: Since it is water-soluble, the body removes excess vitamin C, reducing the risk of toxicity, unlike fat-soluble vitamins.

Demystifying Vitamin Production: C vs. D

The idea that the sun provides all our vitamin needs is a widespread yet inaccurate belief. While sunlight plays a vital role in synthesizing one vitamin, it has no direct role in the production of another. Vitamin C and vitamin D are fundamentally different compounds, with different origins and metabolic pathways in the human body. Understanding this distinction is crucial for maintaining proper nutritional intake and overall health.

The Role of Sunlight in Vitamin D Synthesis

Sunlight is essential for the body's natural production of vitamin D, earning it the nickname "the sunshine vitamin". The process begins when ultraviolet B (UVB) rays from the sun hit the skin. Our skin contains a cholesterol-like substance called 7-dehydrocholesterol. The UVB radiation provides the energy needed to convert this compound into previtamin D3, which is then converted into vitamin D3. The liver and kidneys further process vitamin D3 into the active form that the body can use. This process is not a passive reception of vitamin D but an active, internal chemical synthesis driven by sun exposure.

7-Dehydrocholesterol: A precursor found in the skin.
UVB Radiation: Triggers the conversion of 7-dehydrocholesterol to previtamin D3.
Previtamin D3: An unstable intermediate compound formed in the skin.
Vitamin D3: Formed from previtamin D3 with the help of body heat.
Activation: D3 is finally activated by the liver and kidneys into a usable form.

Why Vitamin C is Different

Unlike vitamin D, humans cannot produce their own vitamin C (ascorbic acid). This inability stems from a genetic mutation in our primate ancestors that deactivated a key enzyme required for vitamin C synthesis. Because of this evolutionary quirk, we must obtain all our vitamin C from external sources, specifically our diet. Sunlight does not contain vitamin C, nor does it trigger any bodily process to create it. In fact, exposure to light and heat can actually destroy vitamin C in food.

Dietary Requirement: Humans must get all vitamin C from food or supplements.
Genetic Limitation: The absence of the enzyme L-gulonolactone oxidase prevents internal synthesis.
Light Sensitivity: Vitamin C is a water-soluble and thermolabile substance, meaning it is easily destroyed by heat and oxygen.

Comparison: Vitamin C vs. Vitamin D

To clarify the misconceptions, here is a breakdown of the key differences between these two vital nutrients:


Feature	Vitamin C	Vitamin D
Source	Primarily fruits and vegetables.	Skin exposure to UVB sunlight; also some foods and supplements.
Body Production	Cannot be synthesized by humans.	Synthesized in the skin via UV light.
Chemical Type	Water-soluble antioxidant (Ascorbic Acid).	Fat-soluble hormone.
Primary Function	Collagen synthesis, immune support, wound healing.	Calcium absorption, bone health, immune regulation.
Body Storage	Not stored for long periods; excess is excreted.	Can be stored in the body's tissues.
Associated Deficiency	Scurvy.	Rickets (in children), osteomalacia (in adults).

Excellent Dietary Sources of Vitamin C

Since the sun cannot provide vitamin C, relying on a balanced diet rich in specific fruits and vegetables is the best approach. While oranges are a well-known source, many other foods offer even higher concentrations of this crucial nutrient. Choosing fresh, raw produce is the most effective way to maximize your intake, as cooking and prolonged storage can significantly reduce the vitamin C content.

Citrus Fruits: Oranges, lemons, grapefruit, and kiwi are classic sources.
Bell Peppers: Sweet yellow peppers have a notably high vitamin C content.
Berries: Strawberries, blackcurrants, and raspberries are excellent sources.
Cruciferous Vegetables: Broccoli, Brussels sprouts, and cabbage are packed with vitamin C.
Tropical Fruits: Papaya, guava, and cantaloupe are rich in this vitamin.
Dark, Leafy Greens: Kale and spinach provide a healthy dose.

Conclusion

In conclusion, the idea that sunlight provides vitamin C is a myth. The sun's energy is a catalyst for our body's production of vitamin D, a process entirely separate from how we get vitamin C. For the latter, our diet remains the sole reliable source. By understanding these distinct nutritional needs, individuals can make informed choices to ensure they are getting sufficient amounts of both vitamins through proper sun exposure for vitamin D and a diet rich in fruits and vegetables for vitamin C. Moderation and a balanced approach are key to maintaining overall health and avoiding misinformation. For more detailed information on dietary needs, consult resources such as the U.S. National Library of Medicine(https://medlineplus.gov/ency/article/002404.htm).

Frequently Asked Questions

No, you cannot get vitamin C by spending more time in the sun. The sun's ultraviolet (UV) rays trigger your body to synthesize vitamin D in the skin, but they do not play any role in producing vitamin C.

Vitamin C comes from your diet, specifically from consuming fruits and vegetables. The human body lacks the enzyme necessary to produce its own vitamin C, making dietary sources or supplements essential.

Severe vitamin C deficiency can lead to scurvy, causing symptoms like fatigue, inflamed gums, easy bruising, and slow wound healing. A consistent lack of sufficient intake can weaken the immune system and impair bodily functions.

Yes, there is a significant difference. Vitamin C is a water-soluble antioxidant obtained from food, crucial for immune function and collagen synthesis. Vitamin D is a fat-soluble hormone produced in the skin from sun exposure, primarily for bone health and calcium absorption.

Yes, cooking can significantly reduce the vitamin C content in food. Because vitamin C is water-soluble and sensitive to heat, methods like boiling are particularly destructive. Steaming or microwaving are better, but eating raw fruits and vegetables is best for maximum retention.

While vitamin D is known to enhance the absorption of minerals like calcium, and vitamin C can help absorb iron, there is no strong evidence to suggest that vitamin D directly improves vitamin C absorption. The two vitamins function largely independently within the body.

Some of the best sources include bell peppers, citrus fruits (like oranges and lemons), kiwi, strawberries, broccoli, and papaya. Many other fruits and vegetables also provide a healthy dose.