(Geriatrics Society Guidelines: Vitamin D May Prevent Falls)
Older patients should receive sufficient vitamin D intake from all sources to lower their risk for falls and fractures, according to a new consensus statement published online December 18 in the Journal of the American Geriatrics Society. Dietary sources, sunlight, and supplements can all contribute to vitamin D levels of around 30 ng/mL (75 nmol/L), which appears to protect against fall-related injuries.
"In studies that achieved average serum levels greater than 25 ng/mL, falls and fracture rates were significantly reduced," James Judge, MD, chair of the American Geriatrics Society's (AGS's) Consensus Statement on Vitamin D Supplementation for Older Adults Work Group, told Medscape Medical News. "The impact on fractures is most likely due to the reduction in falls. In older adults, the impact of vitamin D on bone density is very small, while the impact on falls is measurable."
The consensus statement targets primary healthcare providers, aiming to help them ensure that community-dwelling and institutionalized older adults receive adequate vitamin D from all available sources. In addition to incorporating evidence from recent high-quality research, the statement is based on input from several medical organizations.
The health and well-being of older adults depends on fall and fracture prevention. Previously independent older adults often have to enter long-term care institutions because of repeated falls, and half of all nursing home residents older than 65 years have at least a single fall annually. Hip fracture is one of the most serious consequences of an elderly person falling, as it typically leads to long-term disability, untimely nursing home admission, and premature mortality.
Calcium absorption, healthy bone density, and physical function all require adequate vitamin D levels, and calcium is also vital for bone health. In addition, low Vitamin D levels are linked to muscle weakness, loss of bone strength, and falls and fractures.
Sources of vitamin D include fortified milk and other fortified foods, supplements, and production by the skin when exposed to sunlight (which becomes significantly less efficient with advancing age). In addition, sunlight exposure can cause skin cancer and excess exposure should be avoided. Therefore, the elderly are especially likely to need vitamin D supplementation.
The AGS workgroup agreed with the Endocrine Society (2011), the Osteoporosis Canada Statement (2010), and the majority opinion of the International Osteoporosis Foundation (2010) that a vitamin D [25(OH)D] serum concentration of 30 ng/mL (75 nmol/L) was safe and would ensure the full benefit of vitamin D for older adults.
"For the population of older adults, a total average daily intake from all sources (diet, supplement, and sunlight) of 4000 IU will ensure that 90% of the population will achieve serum 25(OD) D levels of 30 ng/mL," said Dr. Judge, who is also a member of the AGS Clinical Practice Committee, associate clinical professor of medicine at the University of Connecticut School of Medicine in Farmington, and senior medical director of Optum in Eden Prairie, Minnesota.
"This is the serum level that will maximize the protection from falls and fractures that vitamin D can provide," Dr. Judge continued. "The Institute of Medicine (IOM) determined that [a] 4000 IU daily supplement is safe and can be given without risk of toxicity."
The committee used dose–response calculations included in the 2011 IOM report to determine the total vitamin D intake that would achieve recommended serum levels in 92% or more of older adults.
Recommendations for Clinicians to Ensure Adequate Vitamin D Levels in Older Adults
- Review the report and the vitamin D dose–response curve indicating that 1000 IU daily will achieve recommended vitamin D levels in only half of older adults and that substantially higher doses are needed to achieve these levels in 90% of patients.
- Review older patients' vitamin D intake from dietary, sunlight, and supplement sources and discuss strategies to achieve a total vitamin D input of 4000 IU/day.
- Discuss strategies for adequate vitamin D and calcium supplementation with older adults and their caregivers. Available evidence does not support a recommendation for increased vitamin D supplementation without calcium for older people. Supplemental calcium doses in most studies range between 500 and 1200 mg daily.
- Help older adults and their caregivers choose the vitamin D and calcium supplementation schedule they are most likely to follow. Various vitamin D supplements may be taken daily, weekly, or monthly, and different combinations of calcium and vitamin D supplements are available.
Dr. Judge added that clinicians generally do not need to measure vitamin D levels in patients receiving adequate supplementation. The exceptions are patients with obesity, defined as a body mass index (BMI) higher than 30 kg/m2 or body mass higher than 90 kg; malabsorption syndromes; and/or use of medications that either bind vitamin D in the gut or accelerate the breakdown of vitamin D. These medications include cholestyramine and inducers of the cytochrome P450 pathway, such as phenytoin and phenobarbital.
A table included in the AGS statement can help clinicians determine which patients are in need of higher supplement doses and how they can easily determine how much they need based on dietary, sunlight, and supplement exposure.
"We know that in populations, vitamin D levels in the late summer/fall are higher...and our best estimate is that the seasonal variation in total vitamin D generation from sunlight is roughly 1000 IU [a] day," Dr. Judge said. "We know that obese persons have lower vitamin D levels and will need more supplementation. Deeper pigmentation is associated with lower vitamin D levels, but there is evolving information (not available when the statement was completed) that vitamin D levels in African-Americans may not reflect the bioavailability of vitamin D."
Dr. Judge pointed out that most Americans report dietary intake of 150 to 225 vitamin D units daily, with the majority coming from fortified dairy products. Salmon, tuna, mackerel, sardines, and shitake mushrooms provide about 200 IU per serving. Milk products and fortified yogurts provide about 100 IU per 8-ounce (240 cc) serving.
When asked about the need for additional research, Dr. Judge commented that the recommendations of the AGS are based on limited evidence.
"It would be very helpful to clinicians if there were more accurate dosing algorithms than the one presented in this statement," he concluded. "There is limited evidence that 90% of normal-weight older adults (BMI < 25) will achieve recommended serum levels with 1600 to 2000 IU daily supplements. Overweight and obese adults require higher daily supplements — up to 4000 IU daily to achieve serum levels of 30 ng/mL."
Dr. Judge has disclosed no relevant financial relationships.
J Am Geriat Soc. Published online December 18, 2013. Full text
