A diet that needs supplements?

A diet that requires supplements is not a diet we should be consuming.
What if low vitamin-D on a lab test indicated inflammation?
What if this inflammation and low vitamin-D is really a magnesium deficiency?
Should we simply take more vitamin-D and magnesium? Well, what if taking a blast of vitamin-D made our cells more sensitive to hydrogen peroxide and hydrogen peroxide is a known by-product of inflammation?
You can see that supplements are not always the answer.