People need an outside source
Humans do not make enough vitamin C internally to meet the requirement; it is an essential dietary nutrient. Fruits and vegetables are the main food sources. Some foods also have vitamin C added during fortification, so an ingredient may be present even when it is not naturally abundant in that food. [1]
Natural origin is not a different vitamin
NIH ODS reports that supplemental ascorbic acid has bioavailability equivalent to naturally occurring ascorbic acid in foods. That does not make a tablet nutritionally identical to a fruit: foods contain additional components. It does mean the word natural alone cannot establish that a vitamin C molecule will be better absorbed or produce a better clinical result. [1]
An intake example
Imagine a meal supplies 70 mg vitamin C and a fortified drink supplies 30 mg. Together they provide 100 mg, whether or not a separate supplement is used. Verify the food portion and actual label. This accounting example answers where intake comes from; it is not an industrial manufacturing specification or a reason to add a tablet to an already adequate diet. [1]
| Hypothetical source | Vitamin C contribution |
|---|---|
| Food portion | 70 mg |
| Fortified drink | 30 mg |
| Combined intake | 100 mg |
Sources for this article
- Vitamin C - Health Professional Fact Sheet
Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.