The most important functions of calcium in human body have been associated with bleeding conduct nerve impulses , muscle contraction , the construction of the bone tissue . features :
The main function of calcium is structural . The skeleton of an adult male contains about 1.2 kg of calcium. There is a continuous movement of calcium between the skeleton and blood , and other body parts. This is precisely controlled by hormonite.Kaltsiyat also plays a role in cell biology. Calcium may be associated with a wide range of proteins altering their biological activity . This is important in nerve impulse transmission and muscle contraction . Calcium is also required for the clotting of blood , activating clotting factors.
Vitamin D is necessary for the absorption of dietary calcium and thus calcium deficiency may be associated with rickets in children . In adults, calcium deficiency can lead to osteomalacia ( softening of the bones ) . This may be associated with repeated pregnancies lengthy nursing .
Osteoporosis may be caused by calcium deficiency . This involves the loss of calcium from bones and reduced bone density. This causes bones to be fragile and prone to breakage. Bone loss occurs with age in all individuals. This usually occurs after 35-40 years, and includes a reduction in the skeleton. Bone loss is greater in women during menopause . This leads to a reduction in the levels of hormones , oestrogen. After menopause , women are particularly at risk for osteoporosis.
The risk of osteoporosis can be altered by factors other than the diet. Lack of exercise , underweight , smoking and alcohol can increase the risk .
The low level of calcium in the blood and tissues may result in hypocalcaemia. These include sensations of tingling and numbness and muscle twitching . In more severe cases may lead to a muscle spasm . This is called tetany. This is more likely to be due to hormonal imbalance in the regulation of calcium rather than a dietary deficiency . Excess calcium in the blood can cause nausea , vomiting, and calcium deposition in the heart and kidney. This usually results from excessive doses of vitamin D and can be fatal in infants .
Calcium is present in a wide range of foods. Dairy products, green leafy vegetables , nuts and seeds ( almonds , Brazil nuts , sesame seeds ) , tofu and dried fruits are all good sources of calcium for vegetarians . The majority of the flour is fortified with calcium carbonate , and cereals are also good sources . Hard water can also contain calcium. Meat is a very poor source of calcium.
Of dairy products with the highest calcium content are whey , goat cheese and cheese . Vine leaves and kale are among the first in content among vegetables. Oats , corn flour and wheat bran are good sources of calcium. Dried fruits rich in calcium include dried figs , raisins, dates . Of pulses are first soybeans , soy flour and beans . Record in calcium content of nuts is sesame , followed by almonds and flaxseeds .
Calcium balance can be affected by many different factors. Vitamin D is essential for absorption of calcium from the gut . This is because the calcium in the body is carried by a specific protein which requires vitamin D on its synthesis .
A number of substances can inhibit the absorption of calcium. Phytic acid, found in bran, whole grains and raw vegetables of these substances. Ironic acid, a component of dietary fiber, and oxalic acid which is found in certain fruit and vegetables may also be associated with calcium. However, diets , usually high in these acids is not considered to have a significant effect on calcium absorption . Saturated fats can also reduce absorption.
Calcium excreted in the stool, urine and sweat . The loss is approximately equal to the ration for adults. Calcium loss is reduced if its adoption is low. Adaptation to increases and decreases calcium intakes occur. Reduced intake increases the efficiency of absorption . In infants and children calcium is retained for bone growth. Calcium is also lost through breastfeeding.