Vitamin D for Preventing Falls in the Elderly: Less Is Safer

A recent study in the Journal of the American Medical Association (JAMA) Internal Medicine demonstrates that when it comes to vitamin D supplementation in elderly patients prone to falling, more is not better and may in fact be harmful.

Most people know that vitamin D plays a key role in bone health. It maintains normal blood levels of calcium and phosphate, minerals necessary for bone growth and strength, and helps bones absorb calcium. Less well known is the fact that vitamin D also promotes muscle health and strength.[1] People who are deficient in vitamin D often develop weakness in the muscles of the upper legs and arms.[2] These muscle changes can impair walking and increase the risk of falling.

Falls are the leading cause of injury in adults 65 and older.[3] Thirty to 40 percent of older adults living independently at home fall at least once per year. In 5 to 10 percent of cases, these falls result in a fracture, laceration or head injury.[4]

In 2012, the U.S. Preventive Services Task Force (USPSTF), an independent volunteer group of national experts in prevention and evidence-based medicine, recommended vitamin D supplementation to prevent falls in adults 65 and older who are able to live independently at home and are at increased risk for falls (see box, below).

However, there has been uncertainty about what dose of vitamin D is safest and most effective for preventing falls in older adults. The USPSTF recommendation was based mainly on studies that had tested vitamin D at daily doses that are generally considered standard. But more recent studies have shown that supplementation with much higher doses of vitamin D actually increased the risk of falling.

Vitamin D sources

Vitamin D is available in several foods. It is found naturally in some fatty fishes, fish-liver oils, egg yolks and chicken livers. Food producers also have fortified many foods with vitamin D, including milk, orange juice and breakfast cereals. In addition, vitamin D is produced naturally in the skin during exposure to sunlight.

Several forms of vitamin D supplements are available for those people who clearly have inadequate dietary intake and skin production from sun exposure. The most commonly used are cholecalciferol, also known as vitamin D3, and ergocalciferol, or vitamin D2.[6] Other forms of vitamin D include calcitriol (ROCALTROL), alfacalcidol and calcifediol.

Official U.S. nutritional guidelines recommend that healthy adults up to age 70 consume 600 international units (IU) of vitamin D daily.[7] For older adults, the recommended daily allowance increases to 800 IU. Daily vitamin D intake should not exceed 4,000 IU.

USPSTF analysis

Before issuing its 2012 recommendation on vitamin D for preventing falls in the elderly, the USPSTF analyzed data pooled together from nine randomized clinical trials (RCTs) that assessed whether vitamin D supplementation affected the risk of falling in elderly patients living independently at home.[8],[9] The trials together enrolled approximately 5,800 subjects ages 65 or older; most subjects were women. Five trials selected subjects considered to be at high risk of falling because of recent falls or vitamin D deficiency.

For eight trials, subjects in the experimental groups took a daily oral vitamin — most commonly vitamin D2 or D3 at doses ranging from 700 to 1,000 IU — for periods ranging from eight weeks to three years. (In one trial, experimental-group subjects were given a single injection of 600,000 IU of vitamin D.)

The USPSTF’s pooled analysis of the nine trials revealed that vitamin D overall lowered the risk of falling by 17 percent compared with subjects not treated with vitamin D. The USPSTF estimated that for every 10 patients treated, one patient was saved from having a fall. Patients who were actually vitamin-D-deficient appeared to benefit the most.

The USPSTF highlighted one additional RCT published in 2010 after completion of the pooled analysis. The trial involved 2,256 women age 70 or older living in Australia who were randomly assigned to receive a single 500,000 IU oral dose of vitamin D or a placebo each year in autumn or winter for three to five years.[10] The researchers found that subjects in the vitamin D group were 15 percent more likely to experience a fall and 26 percent more likely to suffer a fracture than those in the placebo group. The USPSTF noted that this trial was an outlier, with no other study at the time showing an increased risk of falls after vitamin D supplementation.[11]

However, the most recent RCT, published in JAMA Internal Medicine in February, provides further evidence supporting the conclusion that high-dose vitamin D increases the risk for falls.

The newest trial[12]

Researchers in Switzerland enrolled 200 men and women age 70 or older who were living independently at home and had fallen without serious injury in the prior year. More than half of the subjects had low blood vitamin D levels at the start of the trial. The subjects were randomly assigned to one of three treatments monthly for one year:

• 24,000 IU of oral vitamin D3 (equal to 800 IU daily; low-dose group)
• 60,000 IU of oral vitamin D3 (equal to 2,000 IU daily; high-dose group 1)
• 24,000 IU of oral vitamin D3 (equal to 800 IU daily) plus 300 micrograms of calcifediol, a metabolite of vitamin D (high-dose group 2)

The researchers assessed changes in the subjects’ leg function using standardized tests for walking speed, balance and the ability to repeatedly stand up from a chair. They also measured changes in blood vitamin D levels and the number of falls.

As expected, vitamin D blood levels increased significantly more in the two high-dose groups compared with the low-dose group. However, after six and 12 months of treatment, there was no significant difference in changes on the leg function test scores. Most strikingly, two-thirds of subjects in both high-dose groups experienced falls compared with only half (48 percent) of low-dose subjects. Notably, the subjects who achieved the highest vitamin D levels by the end of the study were the most likely to fall.

A JAMA Internal Medicine editorial about the trial wisely concluded that “it would be prudent to follow recommendations … that people 70 years or older have a total daily intake of 800 IU of vitamin D without routine measurement of [Vitamin D blood] levels.”[13]

What You Can Do

By eating a well-balanced diet with a variety of healthful foods and spending some time in the sun, most people will obtain enough vitamin D for good health. If you are 70 or younger, try to consume 600 IU of vitamin D daily (see table, below, for vitamin D amounts in selected foods). If you are older, consume 800 IU daily.

To avoid a dangerous increase in the risk of falls and fall-related injuries, you should avoid taking vitamin D supplements in doses exceeding 800 IU daily.

Selected Food Sources of Vitamin D[14]

*IU=international units

References

[1] Bischoff-Ferrari HA. Relevance of vitamin D in muscle health. Rev Endocr Metab Disord. 2012;13(1):71-77.

[2] Ibid.

[3] Moyer VA, U.S. Preventive Services Task Force. Prevention of falls in community-dwelling older adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2012;157(3):197-204.

[4] Ibid.

[5] Michael YL, Lin JS, Whitlock EP, et al. Interventions to Prevent Falls in Older Adults: An Updated Systematic Review. Evidence Synthesis No. 80. AHRQ Publication No. 11-05150-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; December 2010.
[6] Pazirandeh S, Burns DL. Overview of vitamin D. UpToDate. Last updated January 15, 2016.

[7] Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: The National Academies Press; 2011.

[8] Moyer VA, U.S. Preventive Services Task Force. Prevention of falls in community-dwelling older adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2012;157(3):197-204.

[9] Michael YL, Whitlock EP, Lin JS, et al. Primary care-relevant interventions to prevent falling in older adults: A systematic evidence review for the U.S. Preventive Services Task Force. Ann Intern Med. 2010;153(12):815-825.

[10] Sanders KM, Stuart AL, Williamson EJ, et al. Annual high-dose oral vitamin D and falls and fractures in older women: A randomized controlled trial. JAMA. 2010;303(18):1815-1822.

[11] Moyer VA, U.S. Preventive Services Task Force. Prevention of falls in community-dwelling older adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2012;157(3):197-204.

[12] Bischoff-Ferrari HA, Dawson-Hughes B, Orav EJ, et al. Monthly high-dose vitamin D treatment for the prevention of functional decline: A randomized clinical trial. JAMA Intern Med. 2016;176(2):175-183.

[13] Cummings SR, Kiel DP, Black DM. Vitamin D supplementation and increased risk of falling: A cautionary tale of vitamin supplements retold. JAMA Intern Med. 2016;176(2):171-172.

[14] National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Accessed April 19, 2016.