Vitamin D

This is Joseph

There seems to be an odd discussion of micronutrients that suggest that large doses are beneficial. I first encountered this via Linus Pauling who posited large benefits to large doses of vitamin C. Now people are positing that vitamin D might help versus covid-19 infections. Now, it is clear that vitamin malnutrition is horrible and it is possible that large doses of vitamins are helpful but I want to do an analogy for why I am pretty sure that there needs to be a high level of evidence. Consider these two paragraphs:

Adequate levels of vitamin D are essential to human health. There are many places where inhabitants may have low levels of vitamin D due to environmental issues and this may adversely impact human health (muscle weakness, pain, fatigue and depression are bad). Therefore, it is clear that the more vitamin D we can get people to consume the better.

Adequate levels of macronutrients (calories) are essential to human health. There are many places where inhabitants may have low levels of macronutrients (calories) due to environmental issues and this may adversely impact human health (starvation is bad). Therefore, it is clear that the more macronutrients (calories) we can get people to consume the better.

Obviously, while starving in bad, overeating isn't ideal either. I am always a bit amazed that the default conversation for appropriate intake of micronutrients is not "adequate intake" and not "more is better". Like there is no reason to presume that macro and micro-nutrients necessarily work the same, but one is amazed that the assumption that they are so completely different is so common.