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.
1 While itâs important to get enough vitamin A, too much can be dangerous. 2  Going over the recommended daily intake can be harmful to your liver, cause fatigue and nausea as well as -- ironically -- hair loss. 3  Make sure you read your vitamin labels and avoid taking multiple doses so you donât over do it.