Nutrition for Optimal Bone Health

Osteoporosis is a silent debilitating disease where bone quality and density are reduced. Bones become very porous and fragile.  Bone loss occurs slowly and progressively, often without symptoms until the first fracture. According to the National Osteoporosis Foundation, an estimated 10 million Americans (8 million women and 2 million men) have osteoporosis. Another 34 million have low bone mass, placing them at increased risk for osteoporosis. Genetics determine the size and density of our bones, but lifestyle factors such as a quality diet, consistent exercise, not smoking and less alcohol use can help to keep our bones strong.  

Quality nutrition helps to build bone mass during the young adult years. Maximum bone density is reached by the early 20s. Preventing osteoporosis is dependent upon making the strongest, densest bones as possible.

What to Include

Although many variables can contribute to bone loss and increased fracture risk, adequate levels of calcium and vitamin D continue to be important. Calcium is a building block for bones, while vitamin D is necessary for calcium absorption.  Our skeleton houses 99 percent of calcium. The calcium in our bones acts as a "reservoir" for maintaining calcium levels in the blood. This is necessary for healthy nerve and muscle functioning. If calcium balance is not achieved in the body, the body will draw on the calcium in bone and result in bone loss.

Calcium

The National Academy of Sciences has developed recommendations for how much calcium (from food and supplement) is needed at every age: 

• Young children 1 to 3 years old should get 700 mg a day. 

• Children 4 to 8 years old should get 1,000 mg per day. 

• Teenagers should get 1,300 mg of calcium a day. 

• Adults up to age 70 should get 1,000 mg per day. 

• Women age 51 and over should get 1,200 mg/day. 

• Women and men age 71 and over should get 1,200 mg per day.  

Milk and dairy products are the most readily available sources of dietary calcium, but other quality non-dairy sources include, sardines and salmon (with edible soft bones), tofu, rhubarb, fortified orange juice and dark, leafy greens. These sources would provide a suitable alternative for those who stay dairy-free or who are following a vegan or vegetarian diet.

Vitamin D

Vitamin D is necessary for the absorption and utilization of calcium. The primary source of vitamin D is exposure to sunlight. For those who live in northern latitudes, the winter sunlight is not strong enough to promote vitamin D formation. Sunscreens also prevent the formation of vitamin D, although they are still encouraged to reduce the risk of sun-induced skin cancer. Good food sources of vitamin D include salmon, tuna, sardines, eggs, fortified orange juice, fortified milk and yogurt as well as fortified breakfast cereals. Unfortunately the amount of vitamin D most people get from their diet is far below the RDA of 400 IU per day. This can be risky for those at risk for osteoporosis. 

Magnesium

Magnesium is added to some calcium supplements. Although it plays only a small role in bone health, it is an important mineral that works with calcium in the body. Magnesium is usually found in very small amounts in multivitamins, and typical diets supply no more than half of the RDA of 400 mg per day. Magnesium in your calcium supplement is not essential, but may be beneficial for overall health.

Vitamin K

Vitamin K, which is found mainly in green, leafy vegetables, plays an important role in calcium regulation and bone formation. Low levels of circulating vitamin K have been linked with low bone density. A report from the Nurses' Health Study suggests that women who get at least 110 micrograms of vitamin K a day are 30 percent less likely to break a hip than women who get less than that. Data from the Framingham Heart Study also shows an association between high vitamin K intake and reduced risk of hip fracture in men and women, and increased bone mineral density in women. Getting one or more servings per day of broccoli, Brussels sprouts, dark green lettuce, collard greens, or kale should be enough to meet the daily recommended target of 120 micrograms per day for men and 90 micrograms per day for women.

What to Avoid

Although a balanced diet can aid in calcium, vitamin D and magnesium absorption, high levels of protein, caffeine, alcohol and salt in the diet are thought to increase calcium excretion. And while no conclusive evidence shows that soft drinks weaken bones, it's best to limit these as well. The Framingham Osteoporosis Study has found that "older women who drink cola every day have lower bone mineral density than those who drink it less than once a month." This may be due to cola's high levels of phosphorous, which may alter the dietary balance between calcium and phosphorous thereby weakening bones.

Supplements

Calcium supplements are better absorbed when taken in small doses (500 mg or less) several times throughout the day. In many individuals, calcium supplements are better absorbed when taken with food. It is important to check supplement labels to ensure that the product meets United States Pharmacopeia (USP) standards.

The Institute of Medicine recommends no more than 4,000 IU of vitamin D per day for adults. To start choose a multivitamin that supplies 1,000 IU of vitamin D per day. If your multi only has 400 IU of vitamin D, consider taking an extra supplement to get you up to 1,000 IU or 2,000 IU per day. Some people may need a larger dose to ensure adequate blood levels, particularly if they have darker skin, spend winters in the northern U.S., or have little exposure to direct sunlight. If you fall into these groups, ask your physician to order a blood test for vitamin D. 

Weight-Bearing Exercise

Physical activity that puts some strain on bones causes the bones to retain and possibly even gain density throughout life. Cells within the bone sense this stress and respond by making the bone stronger and denser. Such "weight-bearing" exercises include weight lifting, jogging, hiking, stair-climbing, step aerobics, dancing, racquet sports, and other activities that require your muscles to work against gravity. Exercise also plays an important role as improving coordination. With greater muscle strength, one can often avoid falls and situations that cause fractures.

Osteoporosis can slow you down and may even prevent you from doing the things you enjoy. Be proactive and consider your bone health today.