Vitamins are essential for the body and generally considered healthy. Some studies even suggest that certain vitamins can help prevent cancer and other serious diseases. Since the body cannot produce these vitamins on its own, they must be obtained externally through foods.
However, when it comes to vitamins, the mantra should not necessarily be “more is better.” High doses of certain vitamins through supplements can lead to overdoses with severe consequences for the body. One potential adverse effect is an increased risk of lung cancer. In this article, we will explore the underlying reasons and the warnings from experts.
Vitamins: Overconsumption Increases Cancer Risk
A vitamin-rich diet is generally seen as a healthy way to lower cancer risk. For example, daily intake of vitamin D could potentially reduce cancer mortality in the population by twelve percent, according to the German Cancer Research Center. However, not all vitamins operate like vitamin D.
While the antioxidant properties of certain vitamins have long been believed to help prevent cancer, experts are pointing out that there is insufficient evidence. Not all the mechanisms and effects of antioxidants on the body are understood.
The German Cancer Society recommends that additional intake of vitamin supplements is advisable only under special circumstances, such as pregnancy or conditions that disrupt the absorption of nutrients like vitamin D or calcium in the gastrointestinal tract. In Germany, this applies to only a few vitamins and minerals. Overconsumption can be harmful and even increase cancer risk, warns the German Cancer Society.
Lung Cancer: Which Vitamin Increases the Risk?
A 2019 study warned that high doses of vitamin B12 were associated with an increased lung cancer risk. However, it is important to note that vitamin B12 itself does not cause cancer; instead, very high doses may stimulate the growth of existing cancer cells. Therefore, the German Cancer Society advises one to check their serum vitamin B12 levels before considering supplementation and to seek medical advice. The effects of vitamin B12 are still being researched.
Photo: Aleksandr Grechanyuk, adobe.stock
Another study from the Journal of Clinical Investigation in 2023 also suggests that the risk of developing a malignant lung tumor may be increased through additional vitamin supplementation. This involves vitamin A, water-soluble vitamin C, and vitamin E—these antioxidants are crucial for healthy skin, teeth, gums, bones, and blood vessels but may also activate a mechanism that benefits cancer cells.
Cancer Risk: How Vitamins Benefit the Tumor
According to the investigation, cancer tumors generate new blood vessels through vitamins. This improves their nutrient supply and leads to faster growth. In contrast, in normal foods like fruits and vegetables, antioxidants are deemed safe. However, one should avoid vitamin supplements like pills, drops, or vitamin-rich drinks, especially since many manufacturers make misleading claims.
