Osteoporosis, heart rhythm, muscle function
Calcium is the most abundant mineral in our body. It constitutes bones and teeth, and is also required in maintaining heart rhythm, muscle function and more. Calcium deficiency can cause rickets and delay development at young age, or lead to osteoporosis at older age.
Genetic variation in several genes is known to reduce absorption of calcium.
Acute levels of calcium are normally a result of taking certain medications or having some rare medical conditions. However, relatively low blood calcium levels can occur due to low dietary intake.
Populations that are generally at high risk for calcium inadequacy include people that avoid dairy products, such as vegans or lactose intolerant individuals. Other diets that lower calcium include consumption of large amounts of protein or sodium, which leads to excess calcium excretion. Certain medical condition, such as osteoporosis, ulcerative colitis, Crohn's disease or celiac disease, can lead to calcium inadequacy as well.
Vitamin D is needed for calcium absorption. Low intake of vitamin D, and not enough exposure to sunlight, lead to low levels of vitamin D and prevent the efficient use of calcium. That's why milk is fortified with vitamin D.
Genetics can predispose to calcium inadequacy through common variations in vitamin D producing genes.
Genetically predisposed individuals should focus on elevating vitamin D levels through diet and sunlight exposure. In addition, diet rich in calcium is needed to meet their body’s demands.
Milk, yogurt, butter and cheeses contain calcium that is easily absorbed.
Milk is also a good source of phosphorus and magnesium, which help the body absorb and use calcium.
Other than milk products, sources of calcium are broccoli, collards, kale, mustard greens, turnip greens, and bok-choy or Chinese cabbage, salmon and sardines canned with their soft bones, almonds, Brazil nuts, sunflower seeds, tahini, and dried beans. Calcium can be consumed through fortified foods such as orange juice, soy milk, tofu, cereals, and breads.
Coffee, alcohol, sodium, and red meat interfere with calcium absorption and retention. Certain dietary fibers, as wheat bran, and also oxalic acid vegetables like spinach and rhubarb can bind with calcium and prevent its absorption.