Vitamin C, also known as ascorbic acid, is an essential vitamin that plays many important roles in the human body. It is a water-soluble vitamin, which means the body does not store it and any excess is excreted in urine. The Recommended Dietary Allowance (RDA) for vitamin C is 75-90 mg per day for adults. This is the amount that meets the needs of about 97% of people. So is 500mg per day considered a lot?
Quick Answer
For most adults, 500mg of vitamin C per day is more than sufficient and considered a high dose. The tolerable upper intake level (UL) for adults is 2,000 mg per day, meaning this is the maximum daily amount that is unlikely to cause harm. So while 500mg is well above the RDA, it is still within the safe upper limit.
How Much Vitamin C Do We Need?
The RDA for vitamin C is based on the amount needed for optimum health and to prevent deficiency. Here are the current RDAs for different groups:
- Infants 0-12 months: 40-50 mg/day
- Children 1-3 years: 15 mg/day
- Children 4-8 years: 25 mg/day
- Children 9-13 years: 45 mg/day
- Adolescents 14-18 years: 75 mg/day (male), 65 mg/day (female)
- Adults: 75-90 mg/day
- Pregnant women: 85 mg/day
- Breastfeeding women: 120 mg/day
As you can see, the RDA for adults is 75-90 mg per day. This is the amount that meets basic nutritional needs and prevents deficiency. However, many experts argue that the minimal RDA is not optimal for preventing chronic disease and achieving optimum health.
Benefits of Higher Doses
Here are some of the evidence-based benefits of getting higher doses of vitamin C:
- Common cold prevention: Studies show that taking 200-500 mg per day may reduce the duration and severity of colds.
- Cancer prevention: Higher intakes around 500 mg per day are linked to reduced risk of certain cancers like esophageal, lung, breast, and pancreatic cancer.
- Heart health: Getting 500 mg per day improves cholesterol levels and lowers heart disease risk.
- Skin health: Vitamin C is required for collagen production and protects against UV damage when applied topically.
- Immune function: It enhances the immune system by stimulating production of lymphocytes and phagocytes.
- Iron absorption: Taking 100 mg with a meal can enhance absorption of iron from plant-based foods.
- Eye health: Higher intakes are linked to reduced risk of cataracts and age-related macular degeneration.
Based on this, taking 500 mg per day may provide health benefits beyond simply preventing deficiency. Many functional and integrative doctors recommend 200-500 mg of vitamin C daily for optimal health.
Are There Risks of Too Much?
Despite being water soluble, vitamin C does have an upper tolerable limit due to potential side effects from very high doses. Here are some of the main risks if you regularly exceed the UL of 2,000 mg per day:
- Digestive issues like diarrhea, nausea, vomiting, heartburn, abdominal cramps
- Kidney stones
- Rebound scurvy – symptoms of deficiency when stopping high dose supplementation
- Iron overload
- Increased oxidative stress
However, these side effects mostly occur with prolonged daily intakes above 2,000 mg. Single doses up to 5,000 mg are unlikely to cause harm. Overall, 500 mg per day is very unlikely to cause any adverse effects in healthy people.
Who May Need More Than 500 mg?
While 500 mg per day meets the needs of most adults, certain groups may benefit from higher intakes:
- Smokers – smoking increases oxidative damage so smokers require 35 mg more vitamin C per day than non-smokers.
- Individuals with certain medical conditions – diseases like cancer, heart disease, diabetes, and autoimmune disorders increase the need for antioxidants like vitamin C.
- Elderly – absorption of vitamin C decreases with age so older adults may need higher intakes.
- Athletes and very active people – intense physical exercise increases vitamin C requirements to optimize performance and recovery.
- Pregnant and breastfeeding women – additional vitamin C is important for baby’s development.
Therefore, certain high-risk and high-demand groups may benefit from more than 500mg per day, preferably under medical supervision. Those with pre-existing conditions should discuss optimal vitamin C intake with their healthcare provider.
What Are the Best Sources?
While high dose vitamin C supplements can help increase intake, there are also many vitamin C-rich foods that can boost your levels. Some of the best dietary sources include:
| Food | Serving | Vitamin C (mg) |
|---|---|---|
| Red bell peppers | 1 medium (149g) | 211 mg |
| Orange juice | 1 cup (248g) | 124 mg |
| Broccoli, cooked | 1 cup (156g) | 102 mg |
| Brussels sprouts | 1 cup (156g) | 96 mg |
| Strawberries | 1 cup (152g) | 89 mg |
| Grapefruit | 1 medium (231g) | 78 mg |
| Kiwi | 1 medium (69g) | 64 mg |
| Orange | 1 medium (131g) | 70 mg |
| Tomato juice | 1 cup (248g) | 50 mg |
Aim for at least 2-3 servings of these vitamin-C rich fruits and vegetables per day. Not only will this help you meet the RDA, but additional produce in your diet provides many other health benefits.
What About Vitamin C Megadoses?
Megadoses refers to taking very high amounts of vitamin C, usually 1,000 mg or more per day. This practice was popularized by Nobel Prize winner Linus Pauling in the 1970s, who claimed it could prevent and treat everything from cancer to the common cold.
However, most modern research shows little added benefit, and possible harm, from prolonged daily megadoses above 2,000 mg. Very high single doses above 10,000 mg may be used intravenously under medical supervision to treat certain conditions like cancer and sepsis.
But there is no good evidence for long term self-administration of megadoses. Sticking within the safe upper limit of 1,000-2,000 mg is optimal for most people.
Can You Get Too Much From Foods Alone?
It’s extremely rare to get excessive vitamin C just from food. Here’s a sample day of vitamin C-rich foods providing 1,200 mg:
- – 1 cup orange juice: 124 mg
- – 1 large red bell pepper: 317 mg
- – 1 cup cooked broccoli: 102 mg
- – 1 medium orange: 70 mg
- – 3/4 cup strawberries: 67 mg
- – 1 medium baked potato: 28 mg
To put this in perspective, you would have to eat over 20 oranges or 30 red bell peppers in a day to exceed the UL of 2,000 mg from food sources alone. It’s virtually impossible to overdose just from eating vitamin C-rich plant foods.
Should You Take a Vitamin C Supplement?
Dietary sources should come first, but if you don’t get enough vitamin C-rich produce, supplements can help you reach optimal intake levels. The benefits really ramp up around 500 mg per day, which is difficult to achieve from food alone.
Look for high-quality ascorbic acid or buffered vitamin C capsules and avoid mega-doses above 1,000 mg. Stick within the 500-1,000 mg range to maximize benefits and prevent side effects.
Those with medical conditions or increased needs may require higher supervised doses. But always speak to your healthcare provider before exceeding standard supplemental levels.
The Bottom Line
For the average healthy adult, 500 mg of vitamin C per day is considered a high dose but still within the safe and potentially beneficial range. While this level exceeds the basic RDA of 75-90 mg to prevent deficiency, it may provide enhanced immune function, antioxidant effects, and protection against chronic disease.
However, some symptoms like diarrhea and nausea can occur above 1,000 mg per day. And very high megadoses over 2,000 mg are possibly unsafe with extended use. Unless your doctor advises otherwise, 500 mg daily from a combination of food and supplements is an optimal intake.
