Healthy Approaches to Managing Osteoporosis
Although many factors can influence bone health, this chapter focuses on the impact of diet and physical activity. These two lifestyle factors are under your control and can have a major impact on the strength of your bones.
Focusing on Nutrition
The quality of your diet can influence the health of your bones. A healthy, well-balanced diet as outlined in chapter 3 should provide the necessary building blocks for healthy bones. Even with the best efforts, however, your diet may fall short of meeting recommended levels. In this case, dietary supplements may help you meet the recommended dietary intake. In particular, calcium and vitamin D are two nutrients of importance for healthy bones, as is adequate protein, which supports muscle and improves absorption of calcium from the diet.
Calcium is a critical mineral for bone health, and the body strongly defends its blood levels of calcium. Humans are not very good at moving calcium from the food eaten into the bloodstream, and this gets worse with age. Therefore, dietary calcium recommendations also increase with age for age-related calcium intake recommendations).
It is vital that growing children get as much calcium in their diets as they can because it may make a large difference in their bone health when they are adults. For adults, studies show that calcium intake at or above recommended levels cannot increase bone density but is very important in preventing bone loss over time. Excessive calcium intake, on the other hand, could contribute to kidney stone formation in certain people, and take more than 2,500 milligrams per day should be avoided.
What are common food and beverage sources of calcium?
As with all nutrients, calcium is most usable by the body when it is ingested in the form of food. Dairy products such as milk, yogurt, and cheese are high in calcium; other foods such as nuts, fish, beans, and some vegetables are less calcium-dense but can help you achieve your calcium requirement. Many nondairy foods are now fortified with calcium, such as orange juice, bread, and cereals, but be sure to read the label because some foods contain more fortification than others.
When you cannot consume sufficient calcium in your diet, supplements in the form of calcium phosphate, calcium carbonate, and calcium citrate may be warranted. Supplements should be evaluated on the basis of their elemental calcium content (usually between 200 and 600 mg per tablet or chew), and not on the overall milligrams of calcium compounds. Because the stomach can absorb only about 500 milligrams of calcium at a time, it is best to spread supplements throughout the day.
Some supplements made from bone meal, dolomite, or unrefined oyster shells may contain substances such as lead or other toxic metals and should be avoided. One way to help ensure that the supplement you are taking is safe and effective is to look for products that have a USP symbol on the label, which stands for United States Pharmacopeia. This is a non-governmental, official public standards-setting authority. Unfortunately, testing of supplements is voluntary, so not all suitable products have this notation.
Vitamin D is another nutrient important to bone health because it helps the body absorb and store calcium. Low vitamin D levels are related to low bone density and increased risk of fractures. The recommended daily intake of vitamin D is 600 international units (IU) for adults and pregnant and lactating women (800 IU for those over the age of 70), which can be obtained from food and sunlight. Vitamin D–rich foods include eggs, fatty fish, and cereal and milk fortified with vitamin D. Based on recent research studies linking vitamin D supplementation to reduced risk of fractures and some chronic diseases, the Institute of Medicine is considering increasing the recommended intakes. Studies suggest that intakes in the range of 800 to 1,000 IU per day of vitamin D are associated with better health outcomes and are well below the 2,000 IU daily limit that would avoid any harmful effects of excess vitamin D.
Vitamin D is sometimes referred to as the sunshine vitamin because when UV rays from the sun make contact with the skin, vitamin D is formed. Minimal sun exposure (to feet, hands, and face) of about 15 to 20 minutes per day is usually enough to get most of the needed daily vitamin D, although this ability does decline with age. Sunscreen can reduce vitamin D synthesis by the skin, and deficiencies may also occur in those who are housebound, reside in extreme northern latitudes, do not consume vitamin D–fortified foods, or have kidney or liver disorders that interfere with normal vitamin D metabolism.
Protein makes up about half of the volume of the bone and about one-third of its mass. Though it may seem confusing, research has shown both pros and cons about protein in the diet and the impact on bone health—but really, it’s the amount of protein that matters. Protein helps balance hormones and improves absorption of calcium from food. Very high protein diets can cause too much calcium to be lost in the urine, but very low protein diets hamper the body’s ability to grow and repair bone. Most older adults do not consume enough protein and should increase their intake to recommended levels in order to support muscle and bone health. Research has shown that increasing protein along with fruits and vegetables in the diet is the best approach for keeping calcium loss at a minimum.
Protein intake requirements are based on a person’s body weight because of the wide variation in lean mass based on body size.