I feel like this just came up recently elsewhere on reddit.
Vitamins don’t just pass through you like a seed. There are variables that can impact how much each one is absorbed, but they are absorbed to some degree just like everything else you eat.
That said – there is no evidence that taking multi-vitamins is beneficial for general health. It is likely that everyone who is otherwise healthy and takes one just because is really just wasting their money – certainly there is no evidence that they are critical to health. They have a place for people who have or are at high risk of vitamin deficiencies, which is not 99% of people who take them.
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