Library.

“Low vitamin B levels, low vitamin D levels, and low iron levels can contribute to symptoms that may be mistaken for depression.”

The evidence supports the claim’s core point. Low iron, low vitamin B levels—especially B12 and folate—and low vitamin D can be associated with fatigue, cognitive slowing, low mood, and related symptoms that overlap with depression. The main caveat is that this does not prove these deficiencies directly cause depressive disorder in every case.

“Supernova explosions create and scatter elements heavier than iron across space.”

The evidence shows that supernovae do both produce some elements heavier than iron and disperse them through space. NASA, DOE, and review literature support that role in nucleosynthesis and galactic enrichment. The main caveat is that supernovae are not the only major source of heavy elements, and may not be the dominant source for the very heaviest r-process elements.