Doses of over 1000 micrograms (mcg) daily of selenium can be toxic. Symptoms of toxicity can include brittleness and loss of hair and nails, vomiting and diarrhea, and skin problems. Tolerable upper intake levels (UL) have been set for selenium.
For infants, the UL is 45 to 60 mcg. For children, the UL ranges from 90 mcg for ages one to three to 280 mcg for ages nine to thirteen. For adolescents and adults the UL is 400 mcg of selenium. To summarize, selenium is important for antioxidant activity in the body. Selenium is also needed to transform thyroid hormone into its active form.
Table 13-2 RDAs and adequate intakes (AI) for selenium for all ages.
Graph 13-1 Selenium content of some common foods.
Copper is an essential trace mineral in animals and many plants. The chemical symbol for copper is Cu from the Latin name for copper, cuprum. There is less than one-tenth of one gram of copper in the human body. Copper can easily accept and donate electrons in the body. Copper can shift between the cuprous state with a single positive charge (Cu+) to the cupric state, which has two positive charges (Cu++). Copper has important roles in energy production in the cell and in scavenging free radicals.
More about Selenium:
0 comments