Why vitamins B6, E and C are not always harmless and when the wrong dosage becomes a danger
In recent years, nutritional supplements have become a part of many people’s daily lives. Vitamins B6, E, and C are often taken “for nerves,” “for immunity,” or “for the heart,” without much thought about dosage and duration. However, scientific studies and clinical experience show that vitamins are not always harmless, especially when taken in high doses and for a long time.
Experts from the National Institutes of Health (NIH) and the European Food Safety Authority (EFSA) point out that, in megadoses, some vitamins no longer behave as nutrients, but as substances with pharmacological effects, capable of causing unwanted consequences. Vitamins B6, E and C in particular are good examples of why the principle “more is better” does not always apply.
Vitamin B6, known as pyridoxine, is needed for nerve function and metabolism, but only in very small amounts. The daily requirement for an adult is about 1.3 to 1.7 mg. When taken for months or years in high doses, especially above 25–50 mg per day, studies published in neurological journals and summarized by the NIH have shown an increased risk of peripheral nerve damage. These injuries manifest with numbness, tingling, burning in the hands and feet, and even difficulty walking. In some cases, improvement after discontinuation of the supplement is slow and not always complete, reports the Telegraph.
also Vitamin E, known as a powerful antioxidant, is not without risk when taken without supervision. The recommended daily dose is about 15 mg, while many supplements contain hundreds of international units (IU). Meta-analyses published in BMJ, Annals of Internal Medicine and Cochrane Collaboration reviews show that the use of high doses, especially above 200–400 IU per day, is associated with an increased risk of bleeding and hemorrhagic stroke. This risk is even greater in people who use aspirin or blood-thinning drugs. The large SELECT study, published in JAMA, found no protective benefits from vitamin E, but raised concerns about its long-term use in high doses.
Vitamin C: , perhaps the most widely used of all, is considered relatively safe, but here too the dosage makes the difference. The daily requirement is around 75–90 mg, while many people take 1 or 2 grams per day “for immunity”. According to NEJM, BMJ and JAMA Internal Medicine, high doses of vitamin C can cause gastrointestinal upset and diarrhea, while in predisposed individuals they increase the risk of kidney stones. Studies show that the immune benefit does not increase proportionally with the dose, while the risk does.
The message emerging from the scientific literature is clear: Supplementation should not be done according to internet advice or trends., but according to the real needs of the body. Vitamins should be taken in the right doses, for the right time and with a clear purpose. Laboratory tests, health condition and the therapy you are using are key factors to consider.
In the end, experts emphasize a simple but very important principle: supplements are not candy and vitamins are not always synonymous with safetyWhen you have dilemmas, medical advice is always the safest solution. /Telegraph/
