Calcium is the most plentiful mineral in the body. Only one percent of the calcium in our bodies is stored in tissues and blood. The majority of the body’s calcium is stored in bones and teeth. Calcium is a building block of bones, teeth, and soft tissues. On a cellular level, calcium regulates muscle and nerve functions. Calcium in the body manages blood vessel dilation and contraction which leads to changes in blood pressure. This is why many medications prescribed for blood pressure work by affecting calcium in the body.
Calcium is absorbed from the foods we eat in the small intestine where it is then transported in the bloodstream. From the bloodstream, calcium is deposited into bones and teeth where it fortifies these structures as well as being stored for future use. The hormone PTH regulates how much calcium is absorbed from food through the small intestine and how much is taken from stores in the bones and teeth. By having a sufficient daily intake of calcium, the body is less likely to take calcium stores from bones which can lead to structural weakness and later, osteoporosis. Healthy calcium intake will also help prevent kidney stones as this is the body’s way of keeping emergency stores for cells when levels are insufficient.
The body needs vitamin D to absorb calcium. Vitamin D is converted to a hormone in the body that activates the intestinal proteins responsible for calcium absorption into the bloodstream. Lactose, which is the sugar contained in milk, also promotes calcium absorption but chocolate milk contains oxalates that are calcium binding and hinder calcium absorption. Vitamin C also helps the body to absorb calcium which is why fortified orange juice is a great way to increase your daily calcium intake.
Dairy foods such as, milk, yogurt, and cheese, are an excellent source of calcium that, because of the lactose, are readily absorbed. There are also plenty of non-dairy sources of calcium. Leafy green vegetables are particularly high in calcium such as, spinach, collard greens, swiss chard, and kale. Other fruits and vegetables like, broccoli, celery, oranges, and papaya contain calcium as well. Calcium can also be found in many nuts and seeds such as sesame seeds, brazil nuts, almonds and flax seeds. Even though dairy products are the sources first thought of for calcium, those who are vegan and lactose intolerant can find many great sources of calcium in the foods they eat.
Calcium is vital for healthy cell function by being the cellular concrete for bones. Calcium is needed for strong nerves and muscles, and calcium is also a factor in proper blood clotting. This is why it is important for the body to have adequate amounts of calcium. The amount of daily calcium needed is different at different stages of our lives. Infants to babies six months of age need 210 mg per day, while babies 7–12 months need 270 mg per day. Growing children from ages one to ten years old need even more, around 800 mg. Teenagers, whose bones are growing at an incredibly fast rate, need the most calcium, about 1,500 mg a day. Adults need about 1,000 mg a day to maintain healthy bone density and adults who are fifty and older should have around 1,300 mg. Woman who are pregnant or lactating need the most at 1,500-2,000 mg.