If you do continue a daily multivitamin, separate it from any interactions, for instance, dont take other vitamins at the exact same time as certain medications like tetracycline antibiotics (all B vitamins can bind with tetracycline in the gut and reduce its absorption)
Other exclusions may apply
Vitamins that often do not need lab tests first The key phrase here is often do not, not never. There are always exceptions
But for most purposes (like weekly maintenance injections), IM is the preferred route at home because its simpler (the vitamins absorb quickly from muscle into the bloodstream over a few hours)
This is especially important for people with digestive issues who may not be able to absorb oral supplements well at all
As a co-therapy like in case of combined collagen crosslinking (CXL) and intrastromal corneal ring segment (ICRS) implantation to treat keratoconic eyes, no adverse effect from the riboflavin injections were reported (32)