Copper is an essential trace mineral, present in all body tissues. It plays a role in the formation of connective tissue, red blood cells, and in the normal functioning of muscles along with the immune and nervous systems. Copper also influences the functioning of the heart and arteries, helps prevent bone defects such as osteoporosis and osteoarthritis, and promotes healthy connective tissues (hair, skin, nails, tendons, ligaments and blood vessels). The daily recommended amounts are 900 mcg for adults, 1000 mcg for pregnant women over 18, 1300 mcg for lactating women over age 18, 200 mcg for infants of 0-6 months, 220 mcg for infants of 7-12 months, 340 mcg for children aged between 1 and 3 years, 440 mcg for children aged between 4 and 8 years, 700 mcg for children aged between 9 and 13 years, and 890 mcg for adolescents aged between 14 and 18 years. Signs of deficiency include bleeding under the skin, damaged blood vessels, hair loss, pale skin, and an enlarged heart. Symptoms also include fatigue and, because copper plays a role in immunity, imbalances can make you more susceptible to infections. Copper is toxic in large amounts, and acute poisoning can lead to nausea, vomiting, diarrhea and even kidney damage, anemia and in - extreme cases - death.