Osteoporosis is characterized by abnormally low bone mass, micro-architectural deterioration of bone tissue leading to increased bone fragility, and a consequent increase in fracture risk. The term osteoporosis is widely used clinically to mean generalized loss of bone, or osteopenia, accompanied by relatively atraumatic fractures of the spine, wrist, hips, or ribs. It is manifested clinically as fractures, and, on noninvasive quantitative imaging tests, as low bone density. Osteoporotic fractures, particularly in aging women, represent a major health problem in industrialized nations. In the United States, approximately 150,000 hip fractures occur annually in women over age 65, with 15 percent to 25 percent of these women experiencing excess mortality or needing long-term nursing home care. While a certain amount of bone loss seems inevitable with the passage of time, the process is not entirely beyond our control. Dietary and lifestyle measures can, to some degree, help maintain bone health. Poor nutrition and other health habits such as smoking, alcohol abuse, and physical inactivity contribute to bone loss. Exercise, especially through activities like walking that put pressure on the weight-bearing bones, stimulates bone remodeling.
Calcium is the most abundant mineral in the human body. Average healthy males have about two and a half to three pounds of calcium while females have about two pounds. Approximately 99 percent of calcium is present in the bones and teeth, which leaves only about one percent in cells and body fluids. While the most important function of calcium involves the maintenance of skeletal health, the small percentage of calcium outside the bones is used to maintain a variety of vital body functions.
Vitamin D is known as the “sunshine” vitamin because it is formed in the body by the action of the sun’s ultraviolet rays on the skin. The fat-soluble vitamin is converted in the kidneys to the hormone calcitrol, which is actually the most active form of vitamin D. The effects of this hormone are targeted at the intestines and bones. Decreased vitamin D intake along with not enough sunlight exposure can cause a vitamin D deficiency. Other causes could be inadequate absorption and impaired conversion of vitamin D into its active form. When vitamin D deficiency occurs, bone mineralization is impaired which leads to bone loss. Rickets, osteomalacia, osteoporosis, crohn’s disease and cancer are associated with vitamin D deficiency.
A study published in the British Journal of Nutrition sought to determine the effects of dietary intervention on bone mineral density (BMD). The study included sixty-six women aged 55 to 65 years who completed the 30-month dietary intervention. The participants were randomized to either a treatment group, which was given1200 mg calcium and 7.5 mug D3 for 12 months followed by 18 months of the same calcium dose, but 22.5 mug D3 and were also enrolled in lifestyle and nutrition counseling, or a control group that received neither the fortified dairy products nor the counseling. The results revealed that the women taking the dairy products had more favorable changes in arm, total spine and total body BMD compared to the control group. The researchers concluded that sufficient dietary intake of vitamin D and calcium combined with lifestyle and nutrition counseling sessions can produce favorable results on bone mineral density in postmenopausal women.1
1 Moschonis G, Katsaroli I, Lyritis GP, et al. The effects of a 30-month dietary intervention on bone mineral density: The Postmenopausal Health Study. Br J Nutr. Apr2010.