October
2007
Calcium
You are not leaving the table until you drink your milk and eat your broccoli! Who would have known at that age how important calcium really was, and still is. Important enough that during times of drought and depression, when nothing went to waste, you would hear of people crushing eggshells into powder and adding it to water to retrieve the calcium. Sounds a little drastic in this day and age since there is calcium charged containers of milk, orange juice, or some Swiss cheese in the fridge, but back then they did what they had to do. In these contemporary times when someone mentions calcium our first thoughts are bones, teeth, and the prevention of Osteoporosis. It makes sense since our bones are the most dense, thus heaviest, parts in our bodies. In fact, 99% of the calcium we ingest is used to repair our bones and teeth. But don?t think that the other 1% is not important, it is essential for nerve transmission, muscular contraction, blood clotting, and a host of metabolic activities. So important that if the body runs low on calcium then it is borrowed from the bones then replaced when available. Being the fifth most common element in the body, the first being water, calcium is considered a mineral, and unfortunately most Americans are calcium deficient.
Though there is a tremendous amount of calcium available in the foods we eat, we use it up at a fantastic rate, with the average person not just using, but losing, approximately 500 mg a day. Various health organizations publish slightly different minimal, recommended, and optimum amounts for differing age groups that can be used as a general guide but your personal health care professional should always be consulted. The recommendations for the daily intake for calcium for children under ten range from 600 mg to 1200mg. At the pubescent and adolescent age this increases from 1200 to 1600mg of calcium per day. The average calcium recommended for most adults ranges from 1000 to 1300mg daily until the age of fifty where it ranges from 1200 to 1600mg. This is a large range of variance for calcium and a little surprising that these health organizations are not a little closer in their recommendations, but one might have to consider their origins, geographical areas, etc. These levels of daily calcium intake are considered average and many other factors, such as diet, smoking, level of physical activity, and medical conditions, should be taken into consideration and consultation with a medical professional is advised.
Though you might get five doctors to agree that you should take calcium, getting them to agree on the same amount could be the difficult part. Because calcium is used, in the most part, in large quantities by the body there appears to be a fairly decent ?margin of error? and this can easily be checked by a urine sample. The parathyroid gland is the primary regulator of calcium and from the reports available it appears that having a little too much calcium is far from risky but a calcium deficiency can lead to a host of problems. Excessive calcium consumption can cause problems with the heart, kidneys, and pancreas but this usually occurs with unknown, pre-existing conditions. One of the most frequently reported origins of excessive calcium is over use of milk and antacids. If the body has extra calcium (unabsorbed) it may use it to bind fatty acids that may otherwise promote colon cancer.
Often myths and misnomers become a factor in decisions on whether or not to take calcium supplements. Many people fear, and link kidney stones, to calcium supplements when in most cases it should exactly the opposite. In most individuals calcium supplements will actually reduce kidney stone risk. Calcium accomplishes this by reducing the body?s absorption of elements known to create kidney stones. The most common of these are called oxalates and are found in foods such as spinach, strawberries, celery, beets, pecans, and peanuts. But by all means do not avoid these foods, their interaction with calcium is a little more complex and we will approach and attempt to explain the calcium?s interaction with other foods and supplements.
Another popular misnomer concerning calcium supplements and other supplements is that they may cause constipation. This is a very old myth that is believed started back in the late 1800s. Fortunately there is no research or clinical data to support this but the thoughts at that time was that calcium hardened your bones and everything in the large intestine.
As mentioned prior, when most of us think of calcium we think about bones and teeth, these dense, calcified, nearly rock hard body frames that take forever to breakdown. So it is not unusual or unjustified to think the same about the absorption of a calcium supplement in our digestive systems. For whatever reason, it seems more questions about absorption originate with the topic of calcium. As a general rule, approved supplements, regardless of their compounds or makeup, including calcium, must meet certain absorption standards. The preferred recommendation for most supplements, calcium again included, (please read all labels) is to be taken with food. The reasoning for this is to slow the supplement down as it travels through the digestive tract to allow total absorption. Calcium, like most supplements, is not absorbed in the stomach, only broken down there. The small intestine is where the majority of calcium is absorbed. Often it is also thought that eating or drinking something acidic such as orange juice or vinegar will assist in breaking down the calcium supplement to achieve better absorption. But this is incorrect because the acid in our stomach is strong enough to break down just about anything and the small intestine where the real absorption occurs has a neutral PH.
Many calcium supplements include vitamin D, and for a very good reason. Calcium and vitamin D are synergistic. There is nothing more important for the body?s absorption of calcium than vitamin D. It?s critical. It?s that important. Without vitamin D, calcium in our bodies through absorption would be nearly non-existent. Now, going back to those health organizations that can?t agree on how much of a certain vitamin or mineral should be consumed, they agree we need vitamin D. How much, again is debated. For young children they recommend, an average, of 250 International Units (IU) if they are breastfed exclusively. Or, if they are not consuming 20oz of vitamin D fortified milk or the equivalent in an infant formula. For adults, the vitamin D recommendation ranges from 400 to 1000 IU daily, and this of course depends on diet, levels of physical activity, and sunlight exposure. Much like calcium, vitamin D has another large margin of error. A very heavy and prolonged dose could cause adverse effects but recent evidence links low levels of vitamin D to an increased incidence of type 1 diabetes, and cancers of the colon, breast, ovaries, prostate, the esophagus, and lymphatic system. If you prefer not take the combination of calcium and vitamin D, then just be sure to take healthy doses of both.
Some foods do contain a calcium binding compound called oxalates. Oxalates are a naturally occurring compound found in spinach, strawberries, and the others listed earlier. It is also found in dietary, high fiber cereals, such as wheat and oat bran. But this is not nearly as bad as some may imagine. The oxalates do not gather all the existing calcium in the digestive tract and bind it together so it cannot be absorbed. Oxalates inhibit, but they do not completely prohibit absorption. The oxalates in spinach leaves inhibits calcium absorption, but only the calcium contained in its own leaves, and does not completely prohibit calcium absorption. A 100% bran cereal may inhibit calcium absorption from the milk it is mixed with but these effects have been blown out of proportion. While these and a few others do indeed inhibit calcium absorption, for the most part they are small and insignificant.
Calcium does compete with magnesium for absorption but this can be easily rectified by alternating their intake. The other foods and the bad guys, smoking, sodium, caffeine, some high protein diets, and fast foods, can cause rapid use or high urinary excretion of calcium. Those included in this group may want to consider increasing their intake of calcium to the higher levels of the recommended dosage.