Because it is water-soluble , your body absorbs what it needs and excretes any excess through urine
You might hear about different kinds of B12 used in injections
How to supplement when B12 tests are high Be sure you remove all sources of synthetic cyanocobalamin from your diet (supplements & fortified foods) Consider supplementing with iodine, selenium, and molybdenum which helps activate B2 (a B12 transport helper) Consider supplementing with an active B2 form (Riboflavin-5-Phosphate) - a B12 transport cofactor Consider taking intrinsic factor which helps the gut better absorb B12 Consider pulsing 4.5 mg of lithium orotate (2-3x per week) - helps the B12 transport Only supplement with bioidentical active B12 forms - hydroxocobalamin, methylcobalamin, adenosylcobalamin I know my specific COMT & VDR Taq gene details

Other foot and ankle conditions: Ankle Osteoarthritis (OA) 1stMTP Chronic ankle sprain Mortons neuroma Plantar Fasciitis Sinus Tarsi Syndrome Midfoot Osteoarthritis (OA) Calf Tear Retrocalcaneal and pre-Achilles bursitis Mid-potion Achilles tendinopathy Baxters nerve References FERNANDES, E.D.A., BERGAMASCHI, S.B., RODRIGUES, T.C., DIAS, G.C., MALMANN, R., RAMOS, G.M
In humans, lower levels of the de novo NAD + synthesis precursor Trp have been observed in blood samples of PD patients, indicating disruption of the kynurenine pathway 276,277