l carnitine for irregular heartbeat L-Carnitine L-Carnitine fumarate
Description
Cardiovascular Wellness: L-carnitine and Folic Acid reduce homocysteine levels and support heart health

Int J Vitam Nutr Res 1995;65:211-4

This sounds very similar to creatines story, if you are familiar with that

Systematic review and meta-analysis of cognitive impairment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Vitamin D deficiency and supplementation during pregnancy
