Known at one time as vitamin B4, before being stripped of its essential status, choline is a molecule required by every cell, being especially important for mitochondrial energy production, fetal neurological development, and healthy liver function. It also plays an underappreciated role in the methylation cycle, which bears upon everything from gene expression to cardiovascular health. So it seems inexplicable that such an important molecule could lose its vitamin status.
It tends to be taken for granted that all of our vitamins have been discovered, and yet the entire notion of vitamins is a relatively recent phenomenon. Perhaps because diets were once held relatively constant over generations by their tradition of proven effectiveness, and were comprised of foods much less processed and tampered-with than many of today’s, it seemed that all you had to do was eat the very same foods that kept your parents alive and healthy enough to produce you, and everything would be fine.