UPDATE: OSTEOPOROSIS
A roundup of medical and other interventions that make a difference (or don’t, in some cases)
IN THIS ARTICLE
In this group of oral bisphosphonate users, patients tended to be older and had been on bisphosphonate therapy longer than patients in the high-risk group. Overall, 78% of the oral users who developed ONJ had been taking a bisphosphonate longer than 3 years.
ONJ is most common in older patients who have been taking an oral bisphosphonate for a long time. Even so, the incidence of ONJ remains quite low, and the potential morbidity pales in comparison with the benefit of fracture reduction in appropriately selected patients.
These reports should not deter clinicians and patients from using effective treatments to prevent fracture in osteoporotic patients.
Vitamin D guidelines emphasize its importance and versatility
Hanley DA, Cranney A, Jones G, et al; for the Guidelines Committee of the Scientific Advisory Council of Osteoporosis Canada. Vitamin D in adult health and disease: a review and guideline statement from Osteoporosis Canada. CMAJ. 2010;182(12):E610-E618.
The Institute of Medicine is expected to release a comprehensive report on Vitamin D late this fall. In the meantime, the Guidelines Committee of the Scientific Advisory Council of Osteoporosis Canada has published its own set of guidelines that underscores the importance of adequate vitamin D intake to ensure bone health and help prevent osteoporosis.
Here are a few points taken from these guidelines:
• Vitamin D is an essential nutrient in the prevention of osteoporosis. It may reduce the risk of other medical disorders unrelated to bone and mineral metabolism.
• Vitamin D3 may be better utilized in the body. After synthesis in the skin or dietary ingestion, vitamin D is removed from the bloodstream into various tissues, including the liver, adipose tissue, and muscle. Its biologic half-life is about 60 days, and it is eventually converted to 25-hydroxyvitamin D in the hepatocytes. Vitamin D3 (cholecalciferol) is the molecule synthesized in the skin in response to ultraviolet B radiation, whereas vitamin D2 (ergocalciferol) is derived from irradiation of certain fungi. Both vitamin D2 and vitamin D3 create 1,25-dihydroxyvitamin D, the active form, although there is some evidence that vitamin D2 may not be used in the body as efficiently as vitamin D3. Most vitamin D supplements consist of vitamin D3, but high-dose preparations, available by prescription, are vitamin D2.
• Vitamin D deficiency is a continuum. The term “deficiency” was previously used to describe the advanced clinical effects of chronically low vitamin D. “Insufficiency” described a milder form of deficiency in which reduced absorption of calcium and the resultant mild secondary hyperparathyroidism might increase bone loss.
• Don’t rely on sunlight. Ultraviolet B radiation (wavelength 290–315 nm) promotes synthesis of vitamin D. The amount of exposure needed to achieve adequate vitamin D status depends on latitude, altitude, time of year and day, weather, other environmental characteristics, age, skin pigmentation, clothing, activity, and the amount of skin irradiated. The influence of diet on vitamin D status is minimal, and most circulating vitamin D is derived from exposure to sunlight. Dermatologists recommend that the safest course is to avoid exposure to the sun and to take vitamin D supplements.
• Vitamin D insufficiency has been associated with malignancies (especially colorectal cancer), diabetes, multiple sclerosis, and impaired immune response. The benefits of vitamin D for these nontraditional roles are associated with 25-hydroxyvitamin D levels above 75 nmol/L.
• What is an optimal serum level? To most consistently improve clinical outcomes such as fracture risk, an optimal serum level of 25-hydroxyvitamin D is probably above 75 nmol/L; for most patients, supplementation is needed to achieve this level.
• The recommended vitamin D intake is 10 μg to 25 μg (400–1,000 IU) daily for low-risk adults younger than 50 years, and 20 μg to 50 μg (800–2,000 IU) for high-risk and older adults, with consideration of higher dosages.
• Consider monitoring vitamin D intake. A dosage as high as 50 μg (2,000 IU) requires no monitoring. If a higher dosage is needed, monitoring is appropriate.
An adequate vitamin D level is essential to bone health and can help prevent a number of medical disorders. Vitamin D insufficiency is rampant. Serum measurement of the 25-hydroxyvitamin D level should be considered in high-risk patients. When indicated, adequate vitamin D supplementation should be ensured in all age groups.
Resistance training provides greater benefits for men than for women
Martyn-St. James M, Carroll S. Progressive high-intensity resistance training and bone mineral density changes among premenopausal women: evidence of discordant site-specific skeletal effects. Sports Med. 2006;36(8):683–704.
