Brain tumor research is a relatively modern science that parallels the explosion of molecular biology and modern neuroimaging. While the science is new, Mayo Clinic has a long history of brain cancer treatment and research stretching back over 100 years.
But not all vitamins are water-soluble, and the ones that are lipid-soluble, meaning they like to hang around in your body's fat, don't get flushed out. Instead, if you take too much of a lipid-soluble vitamin over a few weeks to a month, they sit in the liver and can build up to toxic levels, causing problems ranging from weak bones to liver damage, according to Katherine Zeratsky, a registered dietician nutritionist at the Mayo Clinic.
Taking too much vitamin B6 can be harmful because excess amounts of B6 can cause nerve damage. Taking too much vitamin B12 is rare, but excess amounts of B12 may cause complications for people with certain underlying conditions. Consult your doctor before taking vitamin B6 or vitamin B12 to avoid health problems.