Hello, I am a 41 year old male from South Africa. In the last 3 years my health has been slowly deteriorating. Symptoms: - - Heart palpitations - - Feel that im going to faint from time to time - - Stomach problems I went to see 3 specialists (Cardio, gastroenterologist, specialist doctor). No problem could be found. Despite my illness I kept to a regular exercise program. During last year my symptoms got worse. During exercise I collapsed. Symptoms: - - Tingling in hands and feet moving up to my entire body - - Muscle contractions - - This lasted about 10 to 15 minutes I went back to GP and insisted on blood tests including Testosterone. All blood tests were normal except for Testosterone which was very low (8.5 nmol/L [range 8~30]). Since December last year I am on Testosterone replacement therapy (Nebido). New blood tests show that Testosterone is now normal (20 nmol/L). The problem is that I still feel very bad, Symptoms: - - Elevated heart rate (resting heart rate was 50, is now 70) - - Tingling in hands and feet - - Visual disturbances (blurry vision) So I read up (most on this forum) and asked for B12 blood tests. The results were: > B12: 429 pmol/l [range 83 ~ 418] > P-Homocysteine: 15.6 umol/l [range 5.7 ~ 12.9] > S-Folate : 16 nmol/L [range 10~70] Unfortunately the lab could not do MMA. Will look for a lab that can do MMA today. From what I understand from previous posts these results point to a possible functional B12 deficiency. My questions are: 1. - What other blood tests can you recommend to look for the root cause of the problem 2. - What are my treatment options? Thank you very much. Bernard.