SAN DIEGO — Vitamin D deficiency is underdiagnosed in the nursing home population, according to results from a single-center pilot study.
“Vitamin D deficiency has a huge number of ramifications in terms of increasing fall risk and decreasing strength,” Dr. Christine Simonelli said in an interview during a poster session at the annual meeting of the International Society for Clinical Densitometry. “It's also associated with osteoporosis. Nursing home residents are very often vitamin D deficient because the main source of vitamin D is sunlight.”
She and her associates assessed the prevalence of low bone density and vitamin D deficiency in 49 Caucasian residents of a St. Paul-area nursing home. They reviewed the medical charts of all study participants, used a calcaneal ultrasound machine to measure their bone density, and obtained 25-hydroxyvitamin D levels by serum sample.
The mean age of the residents in the study was 85 years, and 38 were female, said Dr. Simonelli, director of osteoporosis services for HealthEast Care System, Woodbury, Minn. Sixteen residents (33%) were taking a multivitamin supplement that contained vitamin D, and 10 (20%) were taking an additional vitamin D supplement.
Serum vitamin D levels ranged from 6 to 74 ng/mL, with a mean of 22.4 ng/mL. In fact, 35 residents (71%) had levels below the recommended range of 30–32 ng/mL.
Residents taking a multivitamin supplement had a mean vitamin D level of 29 ng/mL.
The mean calcaneal T score was −2.5; 45 (92%) had a score below −1.0, while 26 (53%) had a score below −2.5.
Nine residents (18%) had a diagnosis of osteoporosis in their medical records, and 6 of those residents (12%) were on bisphosphonate therapy.
In addition, 11 residents (22%) had a fall in the previous 30 days, while 35 (71%) had a fall in the previous 180 days.
After the researchers adjusted for age and sex, they found that vitamin D levels did not have a significant association with T-score category or fall rate.
“This pilot project was limited to one nursing home and had a small sample size,” the researchers noted in the report. “Bone density study was limited to peripheral scan type and no confirmatory DXA was performed.”
They also acknowledged that “inclusion of wheelchair-bound residents may have affected fall rate, vitamin D levels, and calcaneal ultrasound values.”