Thyroid function tests are blood tests that check the levels of the hormones (chemicals) made by the thyroid gland. Some thyroid function tests also check the level of a hormone made by the pituitary gland in the brain, which acts on the thyroid gland.hyroid function tests are blood tests that check the levels of the hormones (chemicals) made by the thyroid gland. Some thyroid function tests also check the level of a hormone made by the pituitary gland in the brain, which acts on the thyroid gland.
Yes, high intakes of some forms of vitamin A can be harmful. Getting too much preformed vitamin A (usually from supplements or certain medicines) can cause dizziness, nausea, headaches, coma, and even death. High intakes of preformed vitamin A in pregnant women can also cause birth defects in their babies.
Vitamin Overdose. During pregnancy, it is important to get the proper nutrients to foster healthy fetal development. You may be tempted to take a multivitamin in addition to other supplements. However, vitamin overdose can occur when an individual takes more than the recommended daily amount of a vitamin. This can result when taking more than one multivitamin, or when taking individual vitamins in addition to a multivitamin.