Ellie Wilson
MS, RDN, CDN
History
Vitamin C Day was started in 2019 by a skincare company (Skinceuticals ®), when their scientists showed that some Vitamin C can be absorbed by the skin. This is an important find, as Vitamin C is a key nutrient for skin health and production of collagen, a structural protein found in all connective tissues in our bodies. Vitamin C (ascorbic acid) is an essential nutrient – essential means it must be obtained by eating and drinking because humans cannot make it. Vitamin C is important to many body systems, and research is always reaching to better define roles and mechanisms, especially for preventive health efforts like reducing incidence of cancer or heart disease.
Natural Sources
Vitamin C is found in multiple foods, including all citrus fruits, bell peppers, tomatoes, potatoes, strawberries, and cruciferous vegetables including broccoli, cabbage, cauliflower, and Brussels sprouts. Many foods are fortified with Vitamin C, and it may also be a functional ingredient that maintains freshness. It is so commonly available in foods typically eaten by Americans; it is rare to find a deficiency. It was long recognized that citrus fruits contained a substance that prevented scurvy, a disease that killed sailors from the 1500-1800’s, but the nutrient was not actually identified until 1932.
Supplements
Many people increase their intake of Vitamin C via foods and supplements to ward off chronic health issues, or perhaps when a cold is coming on. In the 1970’s, Linus Pawling, a scientist, and proponent of mega dosing Vitamin C, recommended the equivalent of 12-24 oranges, to support overall health. Vitamin C is a water-soluble vitamin, which means our bodies do not store it well. Due largely to Dr. Pawling’s recommendations, it was not uncommon for people to take high potency supplements of 1000 mg or more, but that is rarely recommended now. In fact, though well-recognized as an antioxidant, at very high levels it can become damaging to cells.
Current Guidelines
The Recommended Daily Amount for adults 19 and older is 90 mg for men and 75 for women. Children’s needs are lower and defined by age and stage of growth. High intake over time results in lower absorption once the body’s limited stores are maxed out. Though it is not toxic, the Tolerable Upper Limit (the maximum amount generally recognized will not cause harm) is 2000 mg per day. Excessive Vitamin C can result in nausea and other GI issues. High, excessive intake of Vitamin C can backfire if it is suddenly stopped – a person that pivots from excess to none can develop rebound scurvy. Despite prevalent belief that Vitamin C can prevent colds, research has so far shown limited benefit, though it may be helpful to reduce virus duration.
Food First
Ensuring you get enough Vitamin C is a great motivator for eating more fruits and vegetables, preferably often over the course of the day. The benefits of eating more produce stack up as other nutrients come along for the ride, such as Vitamin A, fiber, bioactive substances (polyphenols) and water. Vitamin C enhances absorption of iron, which is important to children, pregnant women, and anyone with malabsorption due to intestinal issues or perhaps even a medication interaction. To get the best food benefit, pair higher iron foods, like cooked, unprocessed red meats, legumes, and iron-fortified foods with foods high in Vitamin C to enhance natural absorption of iron. Despite prevalent belief that Vitamin C can prevent colds, research has so far shown limited benefit, though it may be helpful to reduce virus duration.
Best Practices
Enjoy a wide variety of fruits and vegetables – the more you eat, the more likely you are to meet the RDA without a supplement. If you are concerned, ask your health care provider or registered dietitian-nutritionist to assess if you would benefit from a supplement and why, as well as ensuring there are no concerns about current medication/supplement interactions by sharing supplement information with your pharmacist. If supplements are needed, keep them lower dose and consider using every other day. The RDA is based on a weekly average – you are sure to get some Vitamin C most days and can fill in gaps with moderate supplementation.