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.
Vitamins come in two forms: water-soluble and fat-soluble. The water-soluble vitamins are vitamin C and the B-complex vitamins. If you take in more than your body can use of these, they end up passing through you as expensive urine. Vitamins A, D, E and K, on the other hand, require fat to dissolve. Your body stores these vitamins, and if you take too much, the amount in your body can build to a harmful level. Tolerable Upper Intake Levels The highest amount of a vitamin you can safely take per day is known as the tolerable upper intake level, or UL.
For a number of reasons, many people arenât getting enough vitamin D to stay healthy. This is called vitamin D deficiency. You may not get enough vitamin D if: 1  You donât get enough sunlight. 2  Your body is usually able to get all the vitamin D it needs if you regularly expose enough bare skin to the sun.3  However, many people donât get enough sunlight because they spend a lot of time inside and because they use sunscreen. Itâs also difficult for some people to get enough vitamin D from the sun during the winter. 2  You donât take supplements. 3  Itâs very difficult to get enough vitamin D from the foods you eat alone. 4  Your body needs more vitamin D than usual, for example if youâre obese or pregnant.