Pyroluria and mental illness

My crazy and overly credulous sister has been talking about pyroluria and how it may explain problems with my brother. Is this alternative mumbo-jumbo or is there some science behind it?

Googling Pyroluria returns 20,000 hits.
Restricting the search to Pyroluria reduces that to 68 hits.
Google Scholar only returns 13 hits.

The Wiki article on Pyroluria reads like nutritional B.S.

If Pyroluria were a real indicator/sympotom/sign of “ADHD, schizophrenia, autism, alcoholism, bipolar disorder and depression” I’d expect there to be a significant body of research concerning it. There isn’t.

Nice methodology.

My understanding of pyroluria is basic – I believe in 1968 it was proposed to be a useful marker for some psychiatric conditions. Further research (including a 1978 AJP paper) showed little correlation. This is not an unusual occurrence in medicine – many biological markers for disease have less benefit than once thought; there is still broad disagreement on whether testing BPH for prostate cancer is worthwhile. Psychiatrists don’t talk about pyroluria these days, but the granola crowd has latched on to some outdated research. I have not read the original articles, just giving my impression. I suspect most Americans get enough vitamin B6 and zinc in their diet. I thought without AA (ariachdonic acid) you can’t make cell membranes or clotting blood – problems not found in most patients with ADHD, etc.

Do you think it would be worthwhile getting blood tests for zinc and B6 deficiencies just to make sure?

Of course you test PSA for prostate cancer.

I do not think routine testing for vitamin B6 or zinc would be valuable but I am not your doctor and Internet advice regarding this is inappropriate.