This mineral belongs to the macro (those that the body requires greater quantity) and is about 1 to 1.5% of the total weight of a person. The major portion of this element (approximately 85%) works with calcium in building bones and teeth, while the remainder is distributed throughout the human body, performing many different functions.

Thus, it is noteworthy that this is one of the core members of deoxyribonucleic acid (DNA), ie, the molecule that are encoded in our individual qualities and is essential in the production of adenosine triphosphate (ATP), made the body uses to store energy. Also part of all cell membranes, mainly in neural tissues (some people call it “brain food”) and allows for proper utilization of carbohydrates and fats.

To make matters worse, phosphorus is also involved in milk secretion, cellular regeneration, kidney function, muscle contraction, blood chemistry balance, growth during childhood and adolescence, maintaining the regularity of the heartbeat and conduction of nerve impulses.

It is worth mentioning that this mineral is also used and valued by other forms of life on earth. For example, to the plant kingdom is essential in the process of photosynthesis, which involves the transformation of nutrients and sunlight into complex molecules that store energy, while for the animal kingdom is essential in harnessing and developing food movement skills and attention.

Obtaining dietary
Because of its wide distribution, virtually all food products containing even a small portion of phosphorus, but it is recognized that the main sources are the same as we provide protein and calcium, because these nutrients are associated with (of course, talking about milk , eggs, meat, fish and seafood).

Whole grains also have this mineral in abundance, but is at the compound called phytin, which humans are unable to take advantage. In turn, Fruits and vegetables contain small amounts of phosphorus, and only legumes (beans, peas, lentils, chickpeas, soy) and nuts (sunflower seeds, pistachios, almonds, walnuts, sesame) highlight fairly for their contribution.

The vast majority of phosphorus from food is absorbed in the upper small intestine (duodenum), in this process comes to compete with iron, magnesium and folic acid (vitamin B9), and when there is excess is excreted through urine .

Also, phosphorus and calcium are in equilibrium in the body, as the abundance or lack of one affects the ability to absorb the other. Thus, while excess phosphorus causes less absorption of calcium, it was found that frequent ingestion of antacid (with compounds of this last item) generates decrease in the level of phosphates in the body.

Recommendations
Phosphorus deficiency, but rarely by their easy availability of food, produce symptoms such as decay, bone and muscle weakness, tremors, poor generation of red blood cells (anemia), inability to speak or articulate words, lack of appetite, respiratory disorders and in severe cases, loss of consciousness, decreased pulse and death.

This problem occurs as a result of other conditions that prevent the absorption or retention of the mineral in the body, such as alcoholism, hyperthyroidism (overactive thyroid), vitamin D, use of medications, and kidney disease.

In counterpart, when this macronutrient is in excess (a condition that is also rare), can combine with calcium to form deposits in soft tissues such as blood vessel walls and muscles.

Such cases occur only in people with severe kidney problems or with very poor functioning in the regulation of minerals.

Finally, it is worth mentioning what the recommended daily requirement of this mineral, according to age:

* Infants 0 to 6 months: 100 milligrams per day (mg / day).
* Infants between 7 and 12 months: 275 mg / day.
* Toddlers (1 to 3 years): 460 mg / day.
* Children 4 to 8 years: 500 mg / day.
* Older children and adolescents (9 to 18 years): 1,250 mg / day.
* Over 19 years: 700 mg / day.

It must be emphasized that it is rare that additional phosphorus is needed to provide for the needs of the organism because the usual diet is usually sufficient to provide the required amount of nutrient.

The recommendations of calcium intake during pregnancy vary widely among countries even with similar populations, with increased intake on the pregnant woman goes from zero to 800 mg / day or more. One reason for this variability is due to the substantial differences in average calcium intake among countries. Intakes of 200-500 mg / day are typical of Latin America, Africa and Asia, where milk consumption is low, whereas in northern European countries, North America and Australia is about 1000 mg/día2. In addition, calcium diets derived mainly from plant foods may have compounds that interfere with calcium absorption and reduce its bioavailability.

How can some degree of adaptation occur in groups that typically consume diets low in calcium, often expert committees take into account the average consumption of the mineral to fix the recommendations consistent with this and therefore these recommendations would apply only to groups consuming a specific diet in a certain region.

Another reason for the variability in calcium recommendations are due to the current state of ignorance about the mineral requirements for human reproduction and lactation. In general, these have been calculated by adding to the non-pregnant women or infants, the amount covering the cost of calcium for fetal growth and milk production. However, it is possible that alterations in the absorption and excretion mediated by metabolic changes, may compensate for these extra needs without requiring major changes in diet.

Although the scientific evidence for calcium economy during human pregnancy is very limited, in theory, approximately 200-300 mg of calcium per day are deposited in the fetal skeleton during the third quarter of gestación3. If the pregnant woman’s diet does not provide enough calcium for fetal development, fetal growth could be affected adversely, or calcium could be released from the maternal skeleton which is over 98% of the mineral, with possible long-term effect health of the mother. However, because it absorbs about one third of dietary calcium, it is possible that changes in the absorption, metabolism and excretion can ensure enough calcium to the placenta without recourse to the maternal skeleton or need large increases in food intake. In summary, inadequate calcium intake during pregnancy may affect the fetus and its growth. The recommendations must be based on the particular situation of each pregnant so early in pregnancy and its possibilities through the entire pregnancy.

The mobilization of maternal bone calcium could support fetal growth and milk production if calcium intake is inadequate. However, there have been changes in maternal bone mineral content and absorption, excretion and metabolism, but whether these changes are normal or physiological changes are a response to insufficient intake calcio4. Neither is aware of the consequences of these changes on the health of the mother in the short term. The evidence that bone changes that accompany pregnancy and lactation may increase the risk of osteoporosis, is not very conclusive.

It is necessary to take into account the low bioavailability of calcium in the diet, especially high intake of plant foods, which are the largest component of daily nutrition. Dairy products are the only source of food animals, which are consumed at low levels in many countries, particularly in lower income groups. Very little possibility of fulfilling the needs of the mineral with diet alone, even more so during pregnancy when calcium needs increase significantly.

It is known that variations in calcium intake in the diet have a direct result on the measurement of blood pressure changes in calcium concentrations extracelular5. Increasing extracellular calcium levels has to stabilize the membrane of vascular muscle fibers due to reduction of the ionic conductance of the cell membrane which limits the depolarization and the membrane permeability to monovalent cations and bivalentes6-8 and leads by Finally a decrease of vascular tone. Another aspect is that the calcium in the human being is an inducer of phospholipase A2 required to produce acid araquidónico9 and inducer of nitric oxide to form oxide synthase nítrico10. For this complete physiological requirements of calcium is important for maintaining stable vascular tone especially in patients at risk. He believes there is a potential connection between low calcium intake and hypertensive disorders of pregnancy because the incidence of eclampsia is greatest in countries where the daily intake of calcium is basal baja11 (incidence of eclampsia: 0.16-1.2%, average baseline calcium intake: 240-360 mg / day) compared with a lower incidence in countries with higher daily calcium intake at baseline (incidence eclampsia: 0.04-0.09%, average baseline calcium intake: 884-1100 mg / day ). The meta-análisis12 studies have included only placebo-controlled clinical trials and have been the protective effects of calcium for hypertensive disorders of pregnancy, only when basal calcium intake of pregnant women was less than 900 mg / day (OR = 0.32, 95% CI 0.21-0.49).

It is clear that pregnancy is a critical time for calcium intake in the diet of human beings especially in pregnant women at risk. It is also important in the adolescent period where there are higher physiological requirements of the ore by a rapid growth with increased requirements of calcium for the skeleton. The increased intake in the diet or calcium supplementation in the adolescent period is very important as a preventative risk of osteoporosis, especially in women. In the elderly the increase in mineral intake in the diet or calcium supplementation is important in a particular way in deficiency states and at risk for osteoporosis before the decrease in bone resorption and loss of mass ósea13-16.

The lowest income population groups are limited to ensure an adequate intake of calcium in your nutrition by the high cost of foods rich in calcium content as milk and dairy products. There is a better link cost-effectiveness in oral supplementation as a preventive measure for public health programs especially in vulnerable populations.

There are various salts of calcium for oral supplementation, but some differences are observed with prophylactic or therapeutic implications. In an in vitro estudio17 six calcium salts (lactate, carbonate, citrate, gluconate, phosphate and citrate malate) was observed when the salts were subjected to a pH of 2.0, similar to gastric pH, 90% were solubilized in the form ionic, but when the pH was alkaline (pH 7.0, as the bowel), only calcium citrate malate and citrate formed high levels of soluble complexes. In other studies there postmenopáusicas18 women who received 500 mg of elemental calcium from calcium carbonate, calcium citrate and placebo in baseline variation curves for serum calcium was a major change, 94% for calcium citrate respect to the other groups and the same for urinary calcium, 41%, a major shift in the calcium citrate compared to other groups. In assessing the value of parathyroid hormone and bone resorption, calcium citrate was the one that showed a larger decline of the hormone, which means a greater decrease in bone loss with respect to the other groups. Diabéticos13 Another study noted how the supply of calcium from sources other than a decreased parathyroid hormone levels, bone resorption and therefore bone loss. This demonstrated the utility of calcium supplementation in individuals at risk for osteoporosis.

In a meta-análisis19 study to evaluate 15 different jobs, we compared the absorption of calcium carbonate and calcium citrate in 184 subjects and found that calcium citrate has a greater absorption in the range of 22-27% increase in its bioavailability. Other studies in men and women jóvenes14 healthy postmenopáusicas15, 16 showed rise in serum calcium: 76% calcium citrate, compared with serum levels of calcium carbonate, there was a significant correlation with decrease in the level of parathyroid hormone, in bone resorption and therefore ósea14 loss. In a group of 236 postmenopausal women who received 1600 mg of calcium citrate, compared with a placebo group, showed that prolonged administration of calcium citrate for 48 months lowered parathyroid hormone increases related to age and therefore decreased bone resorption and loss of mass ósea15. In vitro studies and in humans humanos13-19 have been advantages in the calcium citrate supplementation in terms of bioavailability, the greater decrease in the levels of parathyroid hormone and bone resorption compared with other salts calcio14-19.

As is clear the need to complete the physiological requirements of calcium during pregnancy, especially in pregnant women at risk for preeclampsia in the last decade witnessed internaciónal12 multi-level studies that have shown benefit only in pregnant women with low dietary intakes of calcium ( <900 mg / day). The research group of the Universidad del Valle in the last decade made two controlled trials in Colombia20, 21, after a clinical trial population in seven departments of the south-western Colombia22, and last year a cooperative study from Colombia, China and Bangladesh in South-East Asia, in which calcium and linoleic acid administered prophylactically to a total of 4,200 pregnant women at risk. There was a low incidence of preeclampsia and its lethality, due to reduction of HELLP syndrome and eclampsia. This reduction is understandable if one considers that all pregnant women were of low socioeconomic status (subsidized health regime) with a low daily calcium intake (<900 mg / day) with high-risk obstetrics, psychological and social. The combination of calcium and linoleic acid has shown a protective effect by increasing the levels of prostaglandin E221 which is the physiological antagonist of angiotensin II, potent vasoconstrictor that are highly sensitive to pregnant women who ultimately develop preeclampsia4.

For oral calcium supplement for prophylaxis in pregnancy, we need a good gastrointestinal tolerance to ensure that it follows the protocol, since it should receive calcium daily during the second half of pregnancy and usually get other micronutrients. For this reason the calcium citrate has advantages because of their low rates of dyspepsia and flatulence which ensures a high compliance rate among pregnant women.

In conclusion, the calcium is an essential mineral for bone deposition and meets a cellular level physiological functions in maintaining vascular tone, so it is important to complete their physiological needs on three life cycles of humans: pregnancy, adolescence and old age, and has a preventive impact on public health.