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 A is essential for good eyesight and cell reproduction; and if you are pregnant, your fetus needs it to develop properly. But because this vitamin is fat-soluble, your body stores the excess, and consuming too much vitamin A can be dangerous.You can experience toxicity symptoms, as well as heighten your risk of certain diseases.itamin A is essential for good eyesight and cell reproduction; and if you are pregnant, your fetus needs it to develop properly. But because this vitamin is fat-soluble, your body stores the excess, and consuming too much vitamin A can be dangerous.