Hi I'm so confused I need advise on what to buy as I'm very sensitive to meds . I am on the holland and barrettt b12 and don't think it's helping . Just gone through amazon and am so confused . I have been luck my gp has changed my regime from 3 monthly to once a month . Next one next week . So I am going to use my hydroxocabalmin Im brand by Auden Mackenzie which worked when I first got loading doses . The second brand I got from pharmacist by a company called focus has not worked or it was the length of time between injections ( 3 months) so please can u all advise the best b12 supplement . Also folic acid supplement and vit d as these are both low also . Symptoms are slowness weakness in legs and balance . Thank u . Please tell me simply the names as I have such bad concentration at the moment .