Recently, a series of fake news has emerged about the Coronavirus emergency. Among these, one of the most viewed was regarding Vitamin C, and stated that excessive consumption could protect against viral infection. In fact, on many e-commerce sites Vitamin C supplements are completely sold out, despite the disapproval of several doctors and other health professionals. Let’s see why this is “fake news.”
VITAMIN C
Vitamin C (Ascorbic Acid) is a molecule produced from sugar (glucose) in various plants and also in the liver of many animals. However, not everyone is able to synthesize it, among which primates and, thus, human beings. For us, vitamin C is an essential vitamin, which means it must be obtained through diet.
Are supplements necessary? No: consuming fresh vegetables provides sufficient amounts of vitamin C (for main sources of vitamin C see the article VITAMINS AND MINERALS TO SUPPORT THE IMMUNE SYSTEM).
According to the Italian Society of Human Nutrition (SINU), the recommended daily intake of vitamin C is 105 mg for men and 85 mg for women.
VITAMIN C FUNCTIONS
This vitamin has several functions: it strengthens the immune system and serves as an antioxidant. It’s important to note that vitamin C is involved in the synthesis (production) of collagen, neurotransmitters, and hormones, as well as in the metabolism of cholesterol, and the absorption of iron.
It also has anti-cancer properties, as it protects our body from the aggression of nitrosamines, carcinogenic products that are formed in the stomach from nitrites (nitrogen substances added as preservatives) that are found in some foods, such as processed meats, alcoholic beverages, and cigarettes. Vitamin C, for example, has proven effective in preventing some forms of cancer, like stomach and esophageal cancer, and laryngeal cancer in heavy drinkers and smokers.
The function of vitamin C on the immune system, which is of great interest in this moment of serious health emergency, consists mainly in promoting:
VITAMIN C DEFICIENCY
Low levels of vitamin C (hypovitaminosis) causes constant weight loss, fatigue, muscle pain, and gingival bleeding. The following groups are most at risk: elderly, smokers, obese individuals, and diabetics. Prolonged vitamin C deficiency causes scurvy, characterized by tissue damage due to alterations in collagen, hematoma, hemorrhages, gingivitis and loss of teeth, and slow wound healing.
Increased vitamin C consumption is recommended if adequate levels are not being met: 1 gram per day is enough to strengthen the immune system without causing side effects.
Consuming higher doses or supplements is therefore not recommended, and should always be done under medical supervision. Furthermore, there was no direct correlation between the vitamin C doses and protection against infections. That is, lack of vitamin C can weaken the immune system, but beyond the recommended dose, there are no further protective effects. Conversely, consuming vitamin C in excess can cause damage, especially if its use is prolonged.
EXCESS OF VITAMIN C
It is unlikely to consume too much Vitamin C from food alone. Our body absorbs only part s of it: between 50 and 80%. Absorption is inversely proportional to dosage (i.e. the more we take and the less we absorb); and the kidneys filter out excess vitamin C through the urine.
Excess vitamin C is most likely obtained through the inadequate consumption of supplements, which can cause headaches, heartburn, vomiting, diarrhea, abdominal cramps, and in some cases, kidney stones.
PRACTICAL ADVICE
It is important to vary your diet as much as possible, by consuming daily fresh and seasonal fruits and vegetables (organic if possible). This provides the body with all the necessary nutrients without the need to resort to supplements. For example, an average orange provides about 70 mg of vitamin C, while a kiwi provides about 64 mg.
To obtain adequate amounts of vitamin C, it is important to alternate cooked and raw vegetables in our weekly diet, since this vitamin is highly sensitive to heat (cooking) and light. It is also important to avoid consuming vitamin C rich foods with caffeine, as it can limit its absorption. For this reason, avoid drinking coffee or tea with orange juice in the same meal. Finally, try to consume fruit and vegetables within a few minutes of cutting them, since vitamin C oxidizes easily when in contact with air, losing its beneficial properties.
If any doubts or questions arise about the need to take a vitamin C supplement, contact our doctor or nutritionist, and follow their directions.
It is true that taking in an adequate amount of vitamin C contributes to good health and immune defenses. The “fake news” lies in suggesting that vitamin C should be consumed in high doses (generally ineffective and results in negative side effects), as well as in claiming that these quantities provide absolute protection from Coronavirus infection.
Even in this difficult moment, it is essential to evaluate the reliability of the information circulating online and on social networks, relying only on the indications of competent professionals (general practitioners and specialists, nutritionists and other health professionals), and avoiding the use of “do it yourself” solutions”. The innovative approach proposed by the Valter Longo Onlus Foundation remains valid because it provided the necessary tools to live a long and healthy life, which our team promotes with passion and dedication.
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