In winter, pharmacy shelves fill up with vitamin C tablets in huge doses, with promises of boosting immunity, preventing colds, and shortening illnesses. In practice – for most healthy people there is no real advantage to this at all. And why? Several simple and clear reasons:
1. There is an abundance of vitamin C – especially in winter
Contrary to what is commonly believed, winter is actually the season richest in natural sources of vitamin C. Winter fruits and vegetables such as peppers, citrus fruits, kiwi, cabbage, cauliflower, broccoli, and strawberries contain particularly high amounts of the vitamin.
Nutritional studies show that in populations that consume a varied diet based on vegetables and fruits – vitamin C deficiency is very rare, even in the winter seasons.
In fact, in Western countries, most people reach and even exceed the daily recommendation through food alone, without even realizing it.
2. It is very easy to reach the required amount from food
The recommended daily amount of vitamin C (about 75 mg for women and about 90 mg for men) is based on studies that examined the level required to maintain proper immune function, collagen production, iron absorption, and antioxidant protection.
Absorption studies have shown that already at a dose of about 100 mg per day, the level of the vitamin in the blood reaches almost complete saturation. Beyond that – absorption drops significantly.
In simple words: One fruit or one vegetable per day already covers the need. There is no physiological advantage to the amount coming from a capsule instead of from a plate.
Here are some examples
- A cup of strawberries (about 150 grams) about 85–90 mg of vitamin C – already more than 100% of the daily amount.
- One red pepper 150 mg to 300 mg of vitamin C – in larger ones, more than double the recommended daily amount.
- One medium orange about 65–90 mg of vitamin C – almost the entire daily amount.
- One large kiwi about 70–75 mg of vitamin C – a full daily amount in one fruit.
- One medium guava about 120–130 mg of vitamin C – one of the fruits richest in vitamin C there is.
- A cup of chopped cabbage (raw) about 30–35 mg of vitamin C
3. Excess vitamin C simply goes out
Vitamin C is a water-soluble vitamin, and the body does not store it. The absorption mechanisms in the intestine and the filtration in the kidneys work in such a way that when there is an excess – it is excreted in the urine within hours. Physiological studies show that already at doses of about 200 mg per day, the level of the vitamin in plasma reaches a maximum. Any addition beyond that does not raise the level in the blood and does not strengthen the immune system.
This is one of the reasons that urine tests after taking supplements show high levels of vitamin C – not because it is “working,” but because it is simply being excreted.
4. High doses have not been proven to prevent illness
One of the strongest myths surrounding vitamin C is that it prevents colds. In practice, large systematic reviews – including Cochrane reviews – found that regular preventive treatment with vitamin C does not reduce the risk of catching a cold in healthy people.
A systematic review published in the Cochrane Database of Systematic Reviews did not find that taking vitamin C prevents colds in healthy people, but at most slightly shortens the duration of the illness.
In some cases, a very negligible shortening of the duration of the illness was found (a few hours to a day), and even that mainly in very specific populations – such as athletes under extreme load or soldiers in harsh field conditions.
In the general public, the clinical effect is almost non-existent, and certainly does not justify daily intake of high doses.
5. Capsules = money flushed down the toilet
When taking 500, 1000, or even 2000 mg of vitamin C per day – most of the amount is not absorbed and does not reach the tissues. The body takes a small amount, and all the rest is excreted.
Moreover, high doses may cause side effects such as gastrointestinal discomfort, diarrhea, and sometimes also an increased risk of kidney stones in sensitive individuals. That is, not only is there no gain – sometimes there is also a price.
For Dr. Maya Rosman’s course: How to improve health and how to lose weight in a sane and sensible way – click here