What affects calcium absorption and excretion?

Calcium absorption refers to the amount of calcium that is absorbed from the digestive tract into our body's circulation. Calcium absorption can be affected by the calcium status of the body, vitamin D status, age, pregnancy and plant substances in the diet. The amount of calcium consumed at one time such as in a meal can also affect absorption. For example, the efficiency of calcium absorption decreases as the amount of calcium consumed at a meal increases.

Age:
Net calcium absorption can be as high as 60% in infants and young children, when the body needs calcium to build strong bones. Absorption slowly decreases to 15-20% in adulthood and even more as one ages . Because calcium absorption declines with age, recommendations for dietary intake of calcium are higher for adults ages 51 and over.

Vitamin D:
Vitamin D helps improve calcium absorption. Your body can obtain vitamin D from food and it can also make vitamin D when your skin is exposed to sunlight. Thus, adequate vitamin D intake from food and sun exposure is essential to bone health.

Pregnancy:
Current calcium recommendations for nonpregnant women are also sufficient for pregnant women because intestinal calcium absorption increases during pregnancy. For this reason, the calcium recommendations established for pregnant women are not different than the recommendations for women who are not pregnant.

Plant substances:
Phytic acid and oxalic acid, which are found naturally in some plants, may bind to calcium and prevent it from being absorbed optimally. These substances affect the absorption of calcium from the plant itself not the calcium found in other calcium-containing foods eaten at the same time . Examples of foods high in oxalic acid are spinach, collard greens, sweet potatoes, rhubarb, and beans. Foods high in phytic acid include whole grain bread, beans, seeds, nuts, grains, and soy isolates. Although soybeans are high in phytic acid, the calcium present in soybeans is still partially absorbed. Fiber, particularly from wheat bran, could also prevent calcium absorption because of its content of phytate. However, the effect of fiber on calcium absorption is more of a concern for individuals with low calcium intakes. The average American tends to consume much less fiber per day than the level that would be needed to affect calcium absorption.
Calcium excretion refers to the amount of calcium eliminated from the body in urine, feces and sweat. Calcium excretion can be affected by many factors including dietary sodium, protein, caffeine and potassium.
Sodium and protein:
Typically, dietary sodium and protein increase calcium excretion as the amount of their intake is increased. However, if a high protein, high sodium food also contains calcium, this may help counteract the loss of calcium.
Potassium:
Increasing dietary potassium intake (such as from 7-8 servings of fruits and vegetables per day) in the presence of a high sodium diet (>5100 mg/day, which is more than twice the Tolerable Upper Intake Level of 2300 mg for sodium per day) may help decrease calcium excretion particularly in postmenopausal women.

Caffeine:
Caffeine has a small effect on calcium absorption. It can temporarily increase calcium excretion and may modestly decrease calcium absorption, an effect easily offset by increasing calcium consumption in the diet. One cup of regular brewed coffee causes a loss of only 2-3 mg of calcium easily offset by adding a tablespoon of milk. Moderate caffeine consumption, (1 cup of coffee or 2 cups of tea per day), in young women who have adequate calcium intakes has little to no negative effects on their bones.


Other factors:
Phosphorus: The effect of dietary phosphorus on calcium is minimal. Some researchers speculate that the detrimental effects of consuming foods high in phosphate such as carbonated soft drinks is due to the replacement of milk with soda rather than the phosphate level itself.

Alcohol: Alcohol can affect calcium status by reducing the intestinal absorption of calcium. It can also inhibit enzymes in the liver that help convert vitamin D to its active form which in turn reduces calcium absorption. However, the amount of alcohol required to affect calcium absorption is unknown. Evidence is currently conflicting whether moderate alcohol consumption is helpful or harmful to bone.
In summary, a variety of factors that may cause a decrease in calcium absorption and/or increase in calcium excretion may negatively affect bone health.

Low cholesterol

Nowadays, cholesterol is becoming a real threat to many people. The main reason behind this is that people tend to consume more products that are rich in saturated fats, such as whole milk dairy products, poultry, and egg yolks.

Additionally, most people also rely on food chains for their daily diet or perhaps on processed foods, especially if their schedule is too hectic to accommodate home cooking. So if you are one of these people who love to eat these kinds of foods, it’s time to reassess your diet and start eating a low-cholesterol diet.

The low-cholesterol diet is a diet low in saturated fat, which helps lower your cholesterol level and protect you from various heart diseases. The foods that should be included in this diet are fat-free dairy products, lean meats, fish and shellfish, skinless poultry, and whole-grain foods. Fresh fruits and green vegetables, especially when combined with large quantities of olive oil and monostaturates, should also be included because these are rich in vitamins and minerals that are good for your body and reduce your risk for high cholesterol. In addition to these, certain foods that contain plant stanols or plant sterols such as cholesterol-lowering margarines and salad dressings can also be added to your diet to boost your body’s LDL-lowering power.

Meanwhile, foods that are high in cholesterol and saturated fats should only be eaten in moderation. If possible, these should not be included in your diet. Avoid liver and other organ meats, egg yolks, full-fat dairy products, high-fat processed meats, and fried foods. Limiting the intake of these foods can greatly reduce your cholesterol levels and decrease your chances of developing heart disease, as well as protect you from future heart attacks.

A simple low-cholesterol diet is a big help to you, but only if you observe and follow these guidelines regularly. Remember that your health is in your hands.

Good Protein

What is Protein?

Proteins are the basic units of the body which are required for nutrition, growth and repair, and affect a huge number of metabolic, enzyme and chemical processes that occur inside the body.

Protein Composed of Amino Acids

Protein actually consists of smaller units called amino acids, which link together in a variety of differing combinations to perform differing functions. Some amino acid chains are created by the body, but some - essential amino acids - must come from outside the body from food. Although all animal and plant cells contain some protein, the amount and the quality of the protein varies considerably.

Best Protein Food Choices Are Proteins Low in Saturates

Protein may come in many forms, but the better type of protein is low in saturated fat. Good protein choices include: fish, lean beef, lean ham, egg whites, whole eggs, chicken breast, turkey breast, pulses, beans, nuts, seeds, soy products and vegetarian protein foods such as quorn and seitan.
How Much Protein Do We Need in Our Diet?

Assuming you choose nutritious protein, low in saturated fat, you can eat anything between 10 and 20 percent of your calories in the form of protein, although according to government guidelines you should not eat less than 45g of protein (adult females) or 55.5g (adult males).

In practice, eating a variety of foods every day is all you need to do in order to ensure an adequate protein intake.