Calcium Information: Absorption, Deficiency Symptoms and Bone Health
What is Calcium?
Calcium is arguably the most important nutrient in your body. As the most abundant mineral it has several important functions. Therefore, there are many calcium health benefits. More than 99% of your calcium is stored in your bones and teeth where it supports their structure and is ready to be called into action for many other critical functions.1 A few of these calcium functions are muscle contraction, blood vessel contraction and expansion, the secretion of hormones and enzymes, and sending messages through the nervous system.2 The amount of calcium in your body fluid and tissues is closely regulated so that these vital body processes function efficiently.
Your bones are continuously breaking down and being formed at the same time. This process of remodelling involves a constant breakdown of bone (resorption) and deposition of calcium into newly deposited bone (bone formation).2 The balance between bone resorption and deposition changes as you age. When you are a child there is a higher amount of bone formation and less breakdown. In early and middle adulthood, these processes are relatively equal. As an aging adult, particularly among postmenopausal women, your bone breakdown exceeds its formation, resulting in bone loss, which increases your risk for osteoporosis (porous, weak bones which can easily fracture).2
Calcium For Healthy Bones
You probably realize the need for Calcium and Vitamin D, but do you know that in the last few years our understanding of the nutritional requirements contributing to healthy bone has expanded to include other critical nutrients?
Vitamin K2, Strontium, and Trace Minerals have been revealed to play an important role in increasing bone mineral density, even among post-menopausal women. Just in 2006 several important studies have all pointed to a much higher level vitamin D being needed than you are getting in your diet or from most calcium supplements. Many people take calcium plus vitamin D for years with little or no results, because these other vital nutrients must also be included to stimulate bone growth.
For the first time in history, there is a clinical study running on all the above-mentioned nutrients in combination. Learn more about the AlgaeCal Bone Health Program.
Calcium Absorption and Calcium Bio-availability
Calcium absorption refers to the amount of calcium that is absorbed from the digestive tract into your body’s circulation. Another term for this is calcium bio-availability.
Calcium absorption can be affected by the amount of calcium in your body, your vitamin D and vitamin K2 status, your magnesium and trace mineral status, your age, pregnancy and certain plant substances in your 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 you consume at a meal increases. A general rule of thumb is to not take more than 500 mg of calcium at a time because the absorption becomes quite low on any amount above that limit.
Factors Affecting Your Calcium Absorption
- Your Vitamin D Status: Vitamin D helps you improve calcium absorption dramatically. 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.
- Your Vitamin K Status: Vitamin K2 works with vitamin D to help osteocalcin hold on to bone building minerals like calcium. Learn more about Vitamin K2 and the benefits of this key ingredient to bone health.
- Your Magnesium Status: Magnesium deficiency alters your calcium metabolism and the hormones that regulate calcium. Please see our magnesium pages for more information on magnesium deficiency, and magnesium benefits.
- Your Age: Your children’s calcium absorption can be as high as 60% because their bodies need calcium to build strong bones.2,11 Your absorption slowly decreases to 15-20% in adulthood and even more as you age.2,11,12 Because your calcium absorption declines with age, recommendations for dietary intake of calcium are higher if you are age 51 and over.
- Certain Vegetables You Eat: Phytic acid and oxalic acid, which are found naturally in some plants, may bind to calcium and prevent it from being absorbed optimally. It is important to note that 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.6
Examples of high oxalic acid foods are spinach, collard greens, sweet potatoes, rhubarb, and beans. Foods high in phytic acid include whole grains, beans, seeds, nuts, grains, and soy isolates.2
- If You Are Pregnant: Current calcium recommendations for non-pregnant women are also sufficient for pregnant women because intestinal calcium absorption increases during pregnancy.2 For this reason, the calcium recommendations established for pregnant women are not different than the recommendations for women who are not pregnant.
More information on Calcium Absorption
The US Surgeon General warns that by 2020, ½ of people over 50 will be at risk for osteoporotic fractures! Not osteoporosis, but worse than that – fractures! Notice that the Surgeon General did not say “those over 80” are at risk of fracture. He said “over 50”! America is one of the top sufferers from Osteoporosis in the world. Why, you ask? Look at the following major government studies.
From 1982 -1986 the US Food and Drug Administration conducted the “Total Diet Study” in which they found Calcium, Magnesium and several other minerals were deficient in several ages and gender groups.
In 1996 USDA completed its “Continuing Survey of Food Intakes of Individuals” corroborated the FDA’s study. The USDA found both boys and girls, men and women deficient in Calcium. The most shocking statistic is for teen girls – 87% do not get recommended intakes of calcium. The Centers for Disease Control, the World Health Organization and others are also warning that we need adequate calcium.
Recent clinical studies show that if you supplement to build bone as children, it’s like depositing “money in the bank” for your old age. Bone loss is inevitable for women and men as we age, but if you started out with a large account it helps later in life. In other words, osteoporosis is largely preventable!
Here is a list of calcium rich foods.
For an excellent calculator telling you how much calcium you have eaten in your diet yesterday, try our Bone Health Calculator.
Calcium excretion refers to the amount of calcium eliminated from your body in urine, feces and sweat. Calcium excretion can be affected by many factors including dietary sodium, protein, caffeine and potassium, but generally not to a great extent.
Get Your Calcium!
You can see from the information above that calcium is incredibly important to your health, that statistically you have a good chance of being calcium deficient, and that calcium is difficult to absorb. It behooves you to find out which are foods rich in calcium and to use our bone health calculator to determine if your current daily calcium intake is adequate.
Learn more about the benefits of calcium.