Osteoporosis is a disease of the skeleton in which the amount of calcium present in the bones slowly decreases to the point where the bones become brittle and prone to fracture. Osteopenia is a preliminary stage of bone calcium loss that is not associated with an increased risk to fracture but suggests the progression to osteoporosis.

The skeleton has a dual function. It provides structural support for the muscles and organs and also serves as a depot for the body’s calcium and other essential minerals. The skeleton holds 99% of the body’s calcium; the remaining one-percent is freed to circulate in the blood and is essential for crucial bodily functions, ranging from muscle contraction to nerve function to blood clotting.

Bone tissue is constantly being broken down and reformed. Bone turnover is necessary for growth, for repair of minor damage that occurs from everyday stress and for the maintenance of other bodily functions. The breakdown, or resorption, of the skeleton is done by cells known as osteoclasts. These cells dig holes into the bone, releasing the small amounts of calcium into the bloodstream that are necessary for other important functions. Osteoblasts are cells that rebuild the skeleton, first by filling in the holes with collagen, (a specialized protein), and then by laying down crystals of calcium and phosphorous. Approximately 10-30% of the adult skeleton undergoes remodeling by this process annually. The balance between breakdown and buildup is controlled by a number of factors including; physical activity, chemical factors and hormonal factors.

Osteoporosis typically occurs with the aging process. It occurs in women more than men; however, it definitely occurs in men.

Hormonal Factors

As we age the anabolic hormones such as estrogen, progesterone, testosterone, DHEA and growth hormone decline. Some of the anabolic hormones, (estrogen), prevent excessive bone loss but do little to cause new bone creation. Other anabolic hormones, (progesterone, testosterone, DHEA and growth hormone), are trophic for bone. This means that they promote new bone formation.  A premature deficiency in any of these hormones can contribute to inadequate bone development and early onset osteoporosis. Young women with delayed onset of menses, (delayed menarche), and women with premature menopause are at increased risk for osteoporosis. Men who have a deficiency in testosterone are at risk for osteoporosis.

Parathyroid hormone is made by the parathyroid glands that reside embedded within the thyroid gland in the neck. Abnormal parathyroid hormone secretion can result in premature osteoporosis. When an individual does not get enough dietary calcium there will be an increase in secretion of parathyroid hormone in order to make calcium available to the non-bony tissues of the body. Inadequate amounts of calcium in the blood and tissues can create life threatening illnesses.

The Calcium Paradox: The Calcium Paradox is a theory that describes the relationship of Calcium, Parathyroid Hormone and Vitamin D to bone health and chronic degenerative diseases of the musculoskeletal system and the vascular system. The principles of this theory are outlined below:

1.      Bone loss is an inevitable part of the aging process. As we age our ability to absorb nutrients decline, our hormonal levels decline and our ability to make new bone declines.

2.      The majority of calcium is stored in bone,(99%). The remaining 1% of calcium is used by the body for a variety of metabolic activities that are essential to the healthy functioning of the vascular system, nervous system and musculoskeletal system. Small variation in serum calcium levels can have significant adverse effects on our health. The body maintains serum calcium levels in a very narrow optimal range. Parathyroid hormone is one of the key ways in which this is accomplished. Parathyroid hormone stimulates the activity of osteoclasts, (the bone break down cells), to release calcium from the bone into the serum.

3.      When serum calcium levels are low, Parathyroid stimulates bone resorption and calcium is provided from bone. When an excess of calcium is released from the bone, the body controls the blood levels by secreting the calcium in the urine and depositing the calcium in soft tissue. It is thought that one cause of the buildup of calcium in blood vessels and other soft tissues is a function of calcium deficiency leading to over secretion of Parathyroid hormone and excess calcium release from the bone into the blood. This theory relates this process to chronic diseases such as the neurodegenerative diseases, (Alzheimers and Parkinsons), Arteriosclerosis, and Osteoarthritis.

4.      The conclusion is that optimal calcium supplementation may help avert many chronic degenerative diseases.

Vitamin D is a hormone in its bioactive form. In order for vitamin D to be active it must have metabolic transformations in the liver and the kidney. We make a precursor vitamin D from cholesterol in our skin. We can also get vitamin D from our food or from supplements. Vitamin D is essential for calcium absorption from the gut and for normal bone growth.

Dietary Factors

Calcium intake is an important determinant of bone density in childhood and young adult life. In fact, one of the main factors in determining risk to osteoporosis is calcium intake in adolescence. This is one of the most important times to insure adequacy of calcium intake through diet and supplementation. Women should consider supplementation during pregnancy and lactation as well as the perimenopausal and postmenopausal years. Calcium supplementation may have other benefits which include a reduction in the risk to hypertension and a reduction in the risk to developing colon cancer. The recommended dose of Calcium for supplementation varies by age, sex and background health issues, (pregnancy, and lactation). In general a dose of 600-1,200 mgs of elemental Calcium is recommended. Calcium Citrate is the most easily absorbable form of Calcium.  A capsulized form is generally easier to absorb than a tabletized form. Product purity can be a concern, as calcium may be contaminated with undesirable substances such as lead. Try to pick a product that is post production tested for purity and potency.

Vitamin D is essential to bone health. We are a society that has tends to minimize sun exposure because of its negative effects on skin aging and its contribution to skin cancer. Twenty to thirty minutes of sun exposure on the face per day will provide the stimulus for Vitamin D formation in our skin. In northern latitudes the sun is not strong enough to stimulate Vitamin D formation and supplementation is recommended. In general it is reasonable to supplement with 400 IU of Vitamin D per day. Individuals with osteopenia or osteoporosis should supplement with 1,200 units of Vitamin D per day. Recent medical literature suggests that adequate Vitamin D levels are associated with a decreased incidence of cancer, (breast, prostate, and colon). In addition, a borderline deficiency of Vitamin D can be associated with musculoskeletal pain. This can be corrected with supplementation.

Essential Fatty Acids are important in so many areas of health. They are important in bone health as well. Fats serve many purposes. They are precursors to messenger molecules called prostaglandins. These messenger molecules are important for a variety of functions including inflammation. The types of fatty acids in our diet influence our ability to form healthy new bone. Saturated fats that form more arachidonic acid will stimulate bone loss. The omega 3 fats such as eicosapentanoic acid, (EPA), and docosahexanoic acid, (DHA), will support new bone formation. EPA/DHA is an important basic supplement for many reasons including bone health. The recommended dose is 2 capsules taken two to three times per day with meals.

There are a many other nutrients that are important for bone health. These include magnesium, silica, boron and Vitamin K. These can be obtained from a good multivitamin. Recently, Strontium, in pharmacologic doses has been shown to induce new bone formation. This may be an alternative to people who can not tolerate or afford the prescription medications.

Insulin Resistance will result in calcium loss from the urine. A diet that minimizes sweets, (soft drinks, candy, dairy desserts, and pastries), and starchy carbohydrates, (bread, rice, pasta and potatoes), will reduce the risk of developing insulin resistance.

Exercise and Bone Health

A mixture of weight bearing exercise will support the health of the musculoskeletal system and promote healthy bone density. Exercise should include aerobic, (walking or jogging) and strength training.

Activities such as Yoga and Tai Chi Chuan promote bone health as we age by preserving our flexibility and balance.

We can measure bone density with a DEXA scan. This is a static measurement of current density. It does not speak to the dynamic process of bone resorbtion or formation. We can measure the current level of ongoing bone loss by measuring the breakdown products of the bony matrix in the urine. This test is called a Urinary Pyrilinks study.

Bone health is a reflection of our overall health. Bone density is not only a measure of our risk of developing fractures secondary to Osteoporosis but a useful way to measure the aging process.