One of the most remarkable papers I have read in the psychiatric literature was about a 57 year old woman who was treated with months of both antipsychotic and antidepressant medications and given two rounds of electroconvulsive treatment before anyone bothered to check her vitamin B12 level.
You are genetically designed to heal. Your physiology is designed to overcome and to make you stronger. Disease is merely the result of living a lifestyle that is incompatible with life and longevity. Even fatal diseases can resolve with lifestyle-based medicine.
Cyanide is found in a wide range of vitamins and foods in a form known as cyanocobalamin, which because it is bound to cobalamin (vitamin b12), significantly reduces the potential for the cyanide to do harm. Cyanocobalamin is actually found in 99% of the vitamins on the market, as it is relatively cheap (recovered from activated sewage sludge or produced through total chemical synthesis), and stable (non-perishable).