Can consuming too much vitamin D be harmful?

It is precisely to assess these risks that German researchers conducted a large-scale study on the effects of high levels of vitamin D in the blood.

A reassuring study on the effects of high supplementation
Several studies have shown a correlation between high blood levels of vitamin D (above the recommended 50 nmol/L) and an increase in blood calcium. A recent German study, conducted on over 445,000 individuals using the UK Biobank database, confirms this correlation. However, it found no negative effects on the kidneys or the cardiovascular system, even in participants with blood vitamin D levels reaching 100 nmol/L.

For comparison, a 2017 study analyzed the effects of a level of 300 nmol/L, corresponding to a daily intake of 15,000 IU. It concluded that these levels, although very rare, did not present any significant danger.