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.
(Health.com) -- Pregnant women could -- and probably should -- consume 10 times more vitamin D than experts currently recommend, according to a new study. Current guidelines for daily vitamin D intake during pregnancy range from 200 international units (IU) per day to 400 IU, the amount found in most prenatal vitamins. For decades, doctors have worried that too much vitamin D during pregnancy could cause birth defects, and under current guidelines anything over 2,000 IU per day is still considered potentially unsafe for anyone, not just pregnant women.