Calcium deficiency is a major problem in the United States. 60% of children under 5 and 40% of children 6 - 11 consume less than their RDA. Of teens, 65% of boys and up to 85% of girls consume less than the recommended amounts. On average, women of all age groups fall far short. These deficiencies, especially in young women, are particularly disturbing because bone built during this time must carry them through the rest of their lives. Calcium is A mineral essential in building and maintaining bones and teeth, as well as in providing efficient muscle contraction and blood clotting. Calcium is found in dairy products, leafy green vegetables (such as spinach, turnip greens and broccoli), sardines and canned salmon with bones and rhubarb. Calcium-fortified orange juice is an excellent source. Deficiency Symptoms include; Loss of bone, and inadequate bone formation that lead to osteoporosis and Vitamin D deficiency. Studies are underway prove possible links between calcium and blood preasure (hypertension), and colon cancer. Toxicity Symptoms: No adverse effects up to 2,400 mg per day for health adults. Generally not well-absorbed higher than 2,400 mg per day. Very high levels may inhibit the absorbtion of other minerals, particularly iron and zinc, and cause constipation.