You basically have two types of vitamins; the
synthetic/isolated vitamins, and the
broad-spectrum vitamers extracted from plants. Most research on synthetic/isolated vitamins show no benefit, or increased risk of cancer, cardiovascular disease, and reduced life-expectancy. (e.g., beta-carotene and alpha-tocopherol) You find the complete opposite from plant-based or plant-extracted vitamins. The key difference here is diversity. For example, most vitamin supplements contain only alpha-tocopherol, which makes it synthetic/isolated. On the other hand, plant-extracted vitamin E supplements include at least 8 different vitamin E vitamers. (tocopherols + tocotrienols)
This danger is applicable to everyone, because more than 99% of vitamin supplements on the market are based off of synthetic or isolated vitamins. Even the so called “natural” vitamins are stripped of vitamers, and are essentially the same as synthetic. Many of the “whole-food” based vitamins are basically synthetic vitamins with added vegetable powder. If you see the yeast Saccharomyces cerevisiae (S. cerevisiae) or the bacteria Lactobacillus bulgaricus (L. Bulgaricus) on the Supplement Facts panel for a particular vitamin, this means that synthetic vitamins were incubated with these microbes in a fermentation process. After the microbes are given a few days to absorb the vitamins, the material is dried, and pressed into tablets. Although these “cultured” vitamins may be more bioavailable than purely synthetic vitamins, they do not contain the same broad spectrum of vitamers found in plant-based vitamins. There are very few brands of vitamins extracted from actual plants.
I just published a comprehensive article on this topic:
https://blog.botanicalcraft.com/vitamins-synthetic-vs-natural-vs-plant-based/