Because they are generally all very safe I usually take median dose used in the studies. At worst, I get no effect and loose some money for the information.

If your micronutrient status is adequate you have no effect. Since its way more expensive or impossible to do status tests then to actually buy the nutrient and give it a chance, I opt for the latter.

The dose also depends on technology used and other potential bioactivators. LET technology, for example is very effective. Pipperine will make a dose lower of anything in general case. Synergy counts too.