A nutritious and healthy diet is the best source of vitamins, minerals and all the elements that are essential for our bodies to function properly. The best way to absorb these elements is through food. The most abundant mineral in the human body is calcium, almost all of which is stored in our bones and teeth.
The recommended intake of calcium can be obtained through healthy diets containing calcium-rich foods. According to Albaneide Peixinho, a nutritionist at the WFP Centre of Excellence against Hunger in Brazil, and Renata Maria Padovani, PhD in Food and Nutrition at the State University of Campinas, calcium absorption is around 30% in dairy products and fortified foods, such as orange juice, tofu and soy milk; and almost twice as high in certain green vegetables, such as Chinese chard, broccoli and cabbage.
In some foods, however, calcium can be poorly absorbed. These are foods such as spinach, sweet potatoes, rhubarb and beans, which contain oxalic acid, which hinders calcium absorption.
Other foods that contain phytic acid do the same. This is the case with whole grain products containing fiber and wheat bran, beans, seeds, nuts and soy isolates. On the other hand, calcium absorption is facilitated by adequate levels of vitamin D.
Some fish are good sources of calcium, such as canned fish with soft, edible bones like sardines, lambari and manjuba, and have amounts of over 400 mg/100g, with lambari reaching 1800 mg of calcium in 100g prepared.
Nuts (especially almonds and Brazil nuts) and seeds (such as linseed) contain between 100 and 250 mg/100g of calcium. Toasted sesame contains around 290 mg of calcium in 30g.
Dark green vegetables such as broccoli, watercress, cabbage and rocket have a calcium content of between 85 and 180 mg/100g.
Certain fruits such as oranges, tangerines, figs, soursop, macauba, tucumã and breadfruit provide 50 to 100 mg per portion.
Calcium-fortified breads, cereals, fruit juices and soy drinks contain significant amounts of calcium.
The importance of calcium
In our bones and teeth, calcium provides strength. But in the rest of our body, it is essential for mediating vascular contraction and vasodilation, muscle function, nerve transmission, intracellular signaling and hormone secretion. Bone tissue serves as a reservoir and source of calcium for these metabolic needs, explain the nutritionists.
On average, people between the ages of 19 and 50 need 1,000 mg/day, with intake recommendations increasing in adolescence, for women over 50 and men over 70, according to a study published in 2011 in The Journal of clinical endocrinology and metabolism.
The World Health Organization recommends calcium supplementation for pregnant women (1,500 mg/day-2,000 mg/day of oral elemental calcium) to reduce the risk of pre-eclampsia in regions where the population has a low calcium intake.