Preventive care: whether you are due for a physical or routine lab testing
In arriving at our criteria we consulted three standard textbooks of medicine (Alstead, Davidson and Price), a consultant haematologist, the librarian at the Royal College of General Practitioners, and the Monthly Index of Medical Specialities
Before taking, speak with your doctor if you are allergic to vitamin b12, have a genetic condition called optic atrophy, have blood in your urine, polycythemia, an ongoing infection, low iron or folate levels, are pregnant or plan to become pregnant, are breastfeeding or plan to breastfeed
As part of the selection process, you should screen websites and companies thoroughly before you make your decision