Can Vitamin B-12 Boost Immunity?

hi i m a male 34yr 6 212 lbs white mixed worked out 4 times a wek, very recent blood test came out that my LBO of the cholesterol was higher than usually normal 240 over 200. i confessed to the doctor that i eat twice a week a nice slice of sirloin and love moderately bacon in my omelet on the weekend and in my burgers. so i m already taking care of that part but i d like to know if vitamin B-12 will ever help, because i never take those and i know they are a good source for my body as my immune system and good for the muscles when i work out. i totally forgot to ask this question to my doctor and i d appreciate if you help me. thx