I've heard vitamin C is not good for your body if you take it in tablet form, but it is good for you if you get it as part of the food you eat. What is your opinion?
Truth be told, there are many claims for vitamin C ranging from its antioxidant abilities to its impact on the common cold. Let me try to address the most common claims for vitamin C in the hopes that this answers your question.
Vitamin C Supplements vs. Foods Containing Vitamin C
Many studies show that people who eat the most fruits and vegetables (generally nine or more servings a day) get less cancers, heart disease, etc. Vitamin C may be one reason for this. However, is it the only player in the game? Of course not. Vitamins and other nutritional factors (e.g., phytonutrients) tend to work better when they are taken in conjunction with other nutrients. There is a difference between vitamin C supplements and an orange, for example. Many nutrition experts recommend foods rich in vitamin C (and other nutrients) over vitamin C supplements because of the possibility that supplements may act differently in the body when they are removed from their natural habitat (i.e., food). For example, we have all heard that vitamin C is an antioxidant and reduces the formation of free radials, which might cause disease. But how many have heard that antioxidants (like vitamin C) may, under some circumstances, become pro-oxidant? A pro-oxidant is something that produces free radicals! So, in theory, taking large doses of vitamin C (or other antioxidants) supplements might produce the very things (free radicals) you are trying to reduce. If taken for years, in theory, the increased free radical production might overwhelm the body’s defenses and promote disease.
Related to this is the fact that many of the claims for vitamin C (and other supplements) stem from research that looks at what happens to people who eat foods rich in this nutrient. That is much different than looking at what happens when people take vitamin C supplements.
Vitamin C and Heart Disease
There is some evidence that low levels of vitamin C may accelerate hardening of the arteries (atherosclerosis) and that vitamin C supplements may decrease this risk. This could have something to do with how vitamin C may lower C-reactive protein (CRP), a compound linked to heart disease (FYI: Some studies show exercise can lower CRP levels also). More research is needed on this issue, but it definitely reinforces the need to get vitamin C in the diet using a quality multivitamin (and quality doesn’t mean mega doses of nutrients).
Vitamin C and Cancer
Studies do show that low vitamin C levels may be linked to some types of cancers, but again, the research stems mostly from people who have vitamin C deficient diets. So the question then becomes, is it low vitamin C levels that promote cancer or is it something else? Or is it a combination of many factors?
Vitamin C and the Common Cold
This is probably the most common claim for vitamin C today, and some research does show that supplements of vitamin C may mildly reduce the severity and duration of cold symptoms (by one to two days at best). Regardless, it’s important to note that the use of high doses of vitamin C does not seem to reduce the incidence of colds in the first place.
Side effects from vitamin C may include diarrhea. Less common is in supplement form, vitamin C may raise blood sugar levels (not good for diabetics). People with special conditions need to speak with their physician before using vitamin C supplements.
The bottom line is we need vitamin C to live. With that said, the research has not shown that all adults need high doses of vitamin C to stay healthy. For most of us, the adult RDA of 90 mg for men and 75 mg for women (and possibly 200 mg for smokers as smoking and chewing tobacco reduces vitamin C levels) seems to be sufficient. If you don’t want to use a supplement, try making this drink in a blender:
- One orange
- Handful of grapes
- Handful of blueberries
- Handful of strawberries
- Handful of baby carrots
- Add water as needed, blend and drink up!
If you do this, you get a lot of vitamin C as well as many other nutrients needed to keep you healthy!