Does vitamin b complex provide enough b12 ? for energy and other benefits?

A healthy well rounded diet provides all the vitamins and supplements that your body needs. B Complex OTC provides 100% or more of daily requirement if your diet is less than optimal. So does a daily multi vitamin. Before starting any alteration in your intake, consult with your GP. If you don't have one, find one.

Unless you have issues with absorption, your diet and B complex will provide enough B12 to meet your needs. B12 does not provide "energy" per se. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV, Flu and Covid vaccines. Wish you good health!