Okay, taking B12 and methylfolate. Things have started, cycles are going, the machine is puffing, but it may go wrong when a deficiency or an excess pops up. So testing on a regular basis would be a wise and hopefully easy thing to do, I guess (apart from noticing changes in mind and body of course). But what are the essentials, the imperatives? Which blood tests should be done? And when, every six months, every three months? Minerals: Zinc, copper, selenium, magnesium, calcium, potassium? Vitamins: B2, B6, C, D? Any ideas?