The question of whether to take supplemental calcium to treat or prevent osteoporosis is discussed often in the media and in my practice. The current dogma is that since bone contains alot of calcium, if you lose bone (osteopenia or osteoporosis), then supplementing with calcium will correct the problem.
The truth is that bone loss does NOT represent a calcium deficiency. The only reason to take extra of anything is if the body is deficient in the substance. The reason that most women ( and a growing number of men) lose bone is primarily because they lose the hormones necessary to grow bone, especially testosterone.
Testosterone is the most important bone building hormone in the human body. The primary reason that bone loss occurs in peri-menopause and beyond is not that women suddenly stopped ingesting enough calcium. It is that the production of the bone building ovarian hormones (i.e. testosterone, estradiol and progesterone) diminishes significantly during this time period, causing the rate of bone loss (osteoclastic activity) to exceed the rate of bone building (osteoblastic activity).
In addition to the loss of hormones, with advancing age there is usually a decrease in physical activity necessary to build bone. Despite the current recommendations, walking is just not enough. Bone, like muscle, grows in response to resistance training (weight training). Walking, though better than sitting on the couch, is not a sufficient enough stress on the bone to cause the osteoblasts to lay down new bone.
Adequate vitamin D is necessary for absorption of dietary calcium from the gut and in the formation of bone. Vitamin D is the most common deficiency I see in my practice. How much vitamin D should you take? Nobody can answer that without testing blood. I have seen patients on the golf course all day in sunny Southern California still significantly deficient in vitamin D ( we lose the ability to convert sunlight to vitamin D with age). One patient in particular golfed 6 days per week, was taking 21,000 units of vitamin D daily, and his blood tests showed he was still deficient!
Remember that taking supplemental calcium is not without risks. Many of you will remember the media hype about a medical report last summer suggesting that calcium supplementation may increase the risk of heart attacks. The report was from the British Medical Journal which reported on a survey of fifteen trials in which participants (all over age 40) were given at least 500 mg of elemental calcium per day. The researchers concluded that calcium supplements increase the risk of myocardial infarction by about 30% over five years.
I have read the full study and although there are some flaws in the study design, my belief is that the authors conclusion in theory is correct.
Remember that calcium is part of plaque, the hard material that builds up in the lining of our blood vessels. You may have heard of a test called a Coronary Calcium Score, which is a CAT scan test that detects the amount of plaque in the blood vessel walls. Where there is calcium, there is plaque. If there is too much calcium in the blood, it can stick to blood vessel walls.
Many patients do not understand that the calcium level detected in blood tests is NOT a reflection of the amount of calcium in the bone.
There is a very narrow range of calcium that the body needs in order to be healthy (approximately 8.5 to 10.2 depending on the lab). Ingesting a few thousand milligrams of calcium in a pill is too much to be taken up by the bones rapidly enough. The excess calcium will stick to tissues, including the lining of blood vessels, and contribute to plaque formation.
So how much extra calcium should one take? That is like asking what size shoe should one wear-it depends completely on the individual. In the active person with good vitamin D and hormone levels (as tested and followed with blood tests), the answer is none. You didn’t need calcium supplementation in your 20’s because you had optimal levels of bone building hormones, were likely more physically active, and still youthful enough to convert sunlight to vitamin D. Age should not be an excuse for not having everything necessary to build bone. As far as using drugs for bone loss, I never prescribe them. You don’t develop a Fosamax deficiency, so why take drugs that have nothing to do with the normal, healthy bone buidling process, and can have serious side effects.