Hi, Welcome To HCM & Thanks For Asking Your Query Here according to your medical history it seems that you have nutritional deficiencies , also there might be problem with the absorption of nutrients in your intestine Vit. B12 level of 450+ ng/L is considered Healthy/Optimal , and clearly your B12 levels are considerably Low , along with this hemoglobin is also on lower side (should be 14+ in healthy male ) so you are both iron and Vit.B12 Deficient and it is highly possible that it may be related to pernicious anemia (a disease in which there are not enough red blood cells due to a lack of vitamin B12) and it should be cured as soon as possible this is not a condition you can treat yourself and i would strongly suggest you to see Your dr , he may prescribe you intramuscular injections of cobalamin which will followed by oral doses of the same further more your doctor will also go for all necessary medical investigations to rule out any other underlying medical condition also you can prevent further vitamin B12 deficiency by eating enough meat, poultry, seafood, dairy products, and eggs. If you don t eat animal products , Your doctor will recommend taking a B12-containing multivitamin and eating breakfast cereal fortified with vitamin B12. I hope it help Thanks & Get well Soon