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.
These vitamins are specially designed to target the needs of mommies-to-be, so if you're not pregnant or trying to get pregnant, you could be missing out on nutrients you need or taking too much of ones you don't need that could make you sick. For example, prenatal vitamins have much more iron than normal women need. Taking too much of it can lead to constipation, vomiting, and nausea, says Dr. Wider. Some also don't have enough calcium for the average woman, so relying just on prenatal vitamins could be detrimental to your health.