Osteoporosis, literally "porous bone," is the result of the gradual loss of bone mass. The loss of bone mass from the skeleton makes the bones susceptible to fragility fractures, which are fractures that occur without the trauma that would ordinarily be needed to cause a fracture. The most common fragility fractures are vertebral, hip and wrist fractures. The vertebral fractures, also called compression fractures, are what cause the curvature of the spine and the resulting loss of height.
The two most common culprits that are mentioned when discussing the etiology of osteoporosis are calcium and estrogen. Calcium is important for many reasons at all ages and inadequate intake has devastating consequences. The loss of estrogen at menopause is also associated with accelerated bone loss.
The 1994 National Institutes of Health (NIH) Consensus Statement on Optimal Calcium Intake defined optimal calcium intake as the levels of consumption that are necessary for an individual to:
1) maximize peak bone mass
2) maintain adult bone mass
3) minimize age-related bone loss
Adolescents and young adults need calcium to maximize their bone "bank account" from which they will withdraw later in life. Adequate calcium intake is needed in middle-aged individuals in order to ensure the maintenance of their adult bone mass and in the elderly, to minimize bone loss in the later years. At any age, calcium homeostasis means that a person's blood will always get the calcium it needs for heart, nerve, muscle and other functions; therefore, the bones will be robbed of calcium if the diet is lacking. The skeleton acts as a giant calcium reservoir since 98-99% of all the calcium in the body is found in bones.
According to the National Osteoporosis Foundation (NOF), 10 million individuals already have osteoporosis and 18 million more have low bone mass. The NOF has determined that osteoporosis is responsible for 1.5 million fractures annually.
Osteoporosis primarily affects women for two reasons. First, women reach a lower peak bone mass than men. Peak bone mass is typically achieved in the late 20's when the skeleton reaches its maximum density and then bone density goes "downhill" over time with the "bone bank account withdrawals." The second reason is that the downhill slope is steeper for women when they reach menopause and lose estrogen.
Enhanced Need for Calcium
Calcium is important for everyone, especially the growing skeleton of children and teenagers (drink your milk!). There are certain situations that create an enhanced need for calcium and, if this need is not met, then the skeleton will be adversely affected.
Postmenopausal Women. In addition to the accelerated bone loss that occurs at menopause, the efficiency of calcium absorption diminishes with age. These two conditions create an enhanced need for calcium. The various guidelines for calcium intake always involve a higher level for postmenopausal women.
Those Using Osteoporosis Prescriptions. All of the prescription products for osteoporosis-estrogen, alendronate, calcitonin and raloxifene-have statements in their product insert that emphasize the need for adequate calcium. In fact, the studies that were conducted for FDA approval of these products involved giving the patients calcium and the prescription product. Taking the prescription product without adequate calcium will diminish the bone benefits.
Pregnancy and Lactation. Pregnant women have a strong need for calcium in order to construct the skeleton of the child. In fact, 30 grams of calcium is deposited into the skeleton in the third trimester alone. If the mother's calcium intake is inadequate, the calcium "bank account" of the mother's skeleton is the source for the child's skeletal development. Studies show that pregnant women have a high absorption calcium from their diet and that their skeletons are not adversely affected long term. In fact, not bearing a child during a woman's lifetime is considered a risk factor for osteoporosis.
Corticosteroid Use. The American College of Rheumatology estimates that 30 million Americans have conditions that may require the use of drugs known as corticosteroids. Conditions like rheumatoid arthritis, asthma and inflammatory bowel disease often involve treatment with a corticosteroid.
Miscellaneous Medications. There are other medications that can adversely affect bone. These medications include methotrexate, cyclosporine, theophylline, thyroid replacement, heparin, anticonvulsants, GnRH analogs, and Depo-progesterone. Depo-progesterone is a contraceptive method that is growing in popularity. Unfortunately, use of this convenient method (injection every three months) is considered a risk factor for the development of osteoporosis.
Feeding the Bones:
Calcium Supplementation
Many consumers are relying on calcium supplements to ensure adequate calcium intake. The calcium supplement market continues to grow as consumers become more aware of the need to feed their bones. The IRI data for mineral supplements showed a 42% sales growth (dollars) for 1998. "Citracal" (ultradense calcium citrate, Mission Pharmacal) and "Caltrate" (calcium carbonate, Lederle) are the top two brands.
Calcium is available in a variety of calcium salts like calcium carbonate, calcium citrate and calcium phosphate. Each salt has a different quantity of calcium per gram of the calcium salt (% elemental calcium). This used to create confusion with consumers, but the current labeling that shows the mg quantity of calcium has resolved this issue.
Many supplements are making statements concerning the quality of the calcium salt. Issues like solubility in the absence of acid, the extent of absorption or bioavailability and the proven benefit to bones are all issues that are attracting more attention. Consumers understand that the calcium must be absorbed into their blood in order to benefit their bones. GNC is counting on this becoming more of a trend and has licensed calcium citrate malate (CCM) from Procter & Gamble. CCM is comparable to the popular calcium citrate and has shown a greater bone benefit than calcium carbonate (Dawson-Hughes B, et al.; A controlled trial of the effect of calcium supplementation on bone density in postmenopausal women. New England Journal of Medicine. 1990; 323: 878-883).
To D or not to D, that is the question. Vitamin D has been growing in popularity over the last few years and the major calcium supplement brands are selling more of their products with vitamin D than without. Vitamin D plays a role in the gastrointestinal absorption of calcium. The body activates vitamin D when the skin is exposed to sunlight and a low level of exposure is needed for adequate vitamin D (about 15 minutes). Studies have shown a seasonal variation of vitamin D levels in people living in northern U.S. states. Vitamin D supplementation is especially beneficial in nursing home patients. Calcium and vitamin D supplementation has been shown to reduce hip fractures in the elderly (Chapuy MC, et al.; Vitamin D3 and calcium to prevent hip fractures in elderly women. New England Journal of Medicine. 1992; 327:1637-1642).
Calcium has also been very popular on the fortification front, from "Total" cereal to "Tropicana" orange juice. Kellogg's new "K-Sentials" highlights the addition of calcium for the bones of growing children. There is even a beer-"Sophie McCall" beer, brewed in California-that boasts added calcium. Fortification with calcium has just begun and it will continue to be popular for a long time.
The Future For Calcium
Increasing Awareness. The awareness of osteoporosis will continue to grow as more products are developed for this condition. Osteoporosis is one of the top areas of pharmaceutical R&D investment. Osteoporosis attention really accelerated with the introduction of prescription agents for osteoporosis that began with the approval of Merck's "Fosamax" in late 1995. No stranger to starting new trends, Merck helped start the cholesterol wave in the late 80's with the first approval of a statin "Mevacor" for cholesterol. A number of companies including Pfizer, Smith Kline and Roche have osteoporosis products in the pipeline. Look for the osteoporosis market to continue to develop as the portfolio of available products develops.
Calcium Companions. Just as vitamin D has grown in popularity, many other entities may come to the forefront as a calcium companion. Among the candidates are magnesium, zinc, manganese, boron, B-6, vitamin K, copper and others. The recently introduced calcium "plus" formulations are already growing in popularity.
Confectionery Calcium. Mead Johnson Nutritionals and Nature Made both recently launched chewable calcium products. Mead Johnson's Johnson's calcium chew-tradenamed "Viactiv"-provides "the calcium you need, the chocolate you crave," while the Nature Made product, available as "Calburst," is sold in chocolate and cherry flavors. Will we see a confectionary craze in the calcium market? Can the market produce a calcium product that will take a bite out of America's daily consumption of about 33 million Hershey's kisses? This will be interesting to watch.
Dental Connection. Chewable calcium products are being offered as a way to avoid tablets and help absorption, although the smaller particles do not ensure solubility and subsequent absorption of calcium. One question that consumers may begin to ask is: What does the calcium product do to my teeth: help or hinder? "Enamelon" toothpaste highlights its calcium component. Will dental differentiation be a market reality in the future?
A Salty Market? Certain calcium salts have experienced strong growth in the last few years. Is this a result of marketing or is there a growing tendency to differentiate among calcium salts? Will bioavailability become a household name as consumers become more savvy?
Natural or Not? There are a few products that can make a "natural" claim, but will this claim become their downfall due to concerns about contamination? For example, calcium from natural sources like oyster shells tends to have a higher lead content. Will lead emerge as a dominant concern? Also, various products promote microcrystalline hydroxyapatite as "comprehensive bone nourishment." It truly is "comprehensive" since ground up animal bones are the source; how ever, as consumers become more aware, will they want to ingest all the entities that are deposited into the bones of animals?
Soy Synergy. The positive bone effect of calcium and soy is a promising combination for the postmenopausal market. Look for products to highlight this combination and try to reach their target market of postmenopausal women.
Premenstrual Syndrome (PMS). Susan Thys-Jacobs, M.D., a very astute researcher in New York, has put forward a connection between deficient calcium and premenstrual syndrome. The high incidence of PMS has led to Dr. Thys-Jacobs to look for simple answers. She is also exploring the use of calcium and high dose vitamin D for migraine headaches, a symptom of PMS. Will Dr. Thys-Jacobs' ideas become mainstream?
Blood Pressure. The American Heart Association recently recommended the DASH diet as part of the initial treatment for high blood pressure. The DASH diet is high in electrolytes, specifically calcium, potassium and magnesium. Look for the DASH dietary direction to gain popularity as people seek dietary answers to their health concerns.
Colorectal Cancer. Dietary patterns have been associated with the risk of colorectal cancer. A recent article in the New England Journal of Medicine (January 14, 1999) concluded: "Calcium supplementation is associated with a significant-though moderate-reduction in the risk of recurrent colorectal adenomas." If the evidence for this beneficial effect builds, then greater consumer motivation to ensure adequate calcium intake will be the result.
Tablet-to-Table Trend. The fortification/functional food frontier for calcium will be one of the most exciting areas in the future. It will be interesting to see the extent of calcium fortification for food products, but it will be even more interesting to see if calcium helps to provide a competitive advantage for food products. Will the addition of calcium be "branded" as it is in the case of Kellogg's K-Sentials? Will we see co-branding emerge as a way to create a tablet-to-table dynamic for functional foods? If a person is comfortable with brand X of calcium, will she be more likely to select a cereal that highlights the addition of brand X calcium? Will tablet sales decline as more calcium appears on the table via functional foods?
The only certain thing is that calcium, the most abundant mineral in human body, will be abundant in the marketplace. Exactly what this will look like is the multi-million dollar question for food, supplement and pharmaceutical manufacturers. NW
About the author:
David Griffith, R.Ph., MBA, is Group Product Director at Mission Pharmacal, concentrating on women's health and osteoporosis products. He was previously Director of Professional Development. Prior to joining Mission Pharmacal, he was Area Sales Trainer and Territory Manager for the Parke-Davis division of Warner-Lambert, where he helped launch "Accupril" and "Nicotrol." Mr.Griffith also teaches a master's level pharmaceutical marketing course at The University of Texas College of Pharmacy and serves as a faculty practitioner at The University of Texas Health Science Center at San Antonio. He is also a registered pharmacist. Mr. Griffith can be reached at Mission Pharmacal, P.O. Box 786099, San Antonio, TX; 210-696-8400 Ext. 217, Fax: 210-696-6040, E-mail: dlgriff@ibm.net.
