Clinical Geriatrics

Decreased Serum Vitamin B12 Concentration is Associated With Greater Fall Risk Among Older Disabled Women: The Women’s Health and Aging Study

Denver, CO—Robert McLean, DSc, Hebrew SeniorLife Institute for Aging Research and Harvard Medical School, Boston, MA, and colleagues examined the associations of serum concentrations of folate, vitamin B12, methylmalonic acid (MMA) and homocysteine with the risk of falling among older disabled women participating in the Women’s Health and Aging Study. Results presented at the ASBMR annual meeting suggest that low vitamin B12 status may be associated with a greater risk of falls among older disabled women. Authors concluded that further studies are needed to explore this relation among a general population of older men and women.

While studies suggest that low B vitamin status and elevated homocysteine concentration are associated with increased fracture risk among older persons, the mechanism is unclear as low bone mass does not fully account for the observed relations. Folate and vitamin B12 deficiencies can lead to lower-extremity sensory and proprioceptive impairment, both of which increase the propensity for falling. An association of these nutrients with fall risk could support a mechanism whereby B vitamins and homocysteine increase fracture risk.

In 1992, non-fasting blood samples were collected from 657 women at baseline (mean age at baseline, 77 yr; range 65-100 yr). Radiodilution assay measured folate (nmol/L) and vitamin B12 (pmol/L), and MMA (nmol/L) and homocysteine (mmol/L) were assessed via mass spectrometry. Quartiles of serum measures were created (Q1 = low). Self-report ascertained the number of incident falls after baseline at six follow-up examinations occurring generally at 6-month intervals. Negative binomial regression calculated the relative rate (RR) of falls, and 95% confidence intervals (CI), over follow-up for quartiles of each serum measure, adjusting for age at baseline (yr) and the number of falls reported in the year prior to baseline (0, 1, ≥ 2). Median follow-up time was 3.1 years (range 0.5-5.6). Falling at least twice over follow-up was reported in 41% of women. Those in vitamin B12 Q1 and Q2 had a 40-57% increased rate of falls as compared to Q4 (referent). Participants in homocysteine Q4 tended to have a 25% increased rate of falls as compared to Q1 (referent), although the CI included the null value. According to the authors, neither folate nor MMA were associated with the rate of falls.

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Low Vitamin D Predicts Bone Loss in Breast Cancer Patients Taking Aromatase Inhibitors

Denver, CO—Baseline 25-hydroxyvitamin D (25OHD) level is a predictor of aromatase inhibitor (AI)–associated bone loss, and women with low 25OHD are at risk for bone loss at 6 months of AI therapy, according to results presented at the ASBMR annual meeting. Researchers concluded that future studies are needed to determine whether aggressive vitamin D replacement will be able to prevent bone loss in women taking AIs for breast cancer. According to researchers, suboptimal vitamin D levels had been reported in as much as 88% of women with breast cancer who were on AI therapy. However, there are no studies investigating whether suboptimal 25OHD levels are an important determinant of bone loss in patients on AI.

Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DXA) and 25OHD was measured by radioimmunoassay. Participants were advised to take 1200 mg of calcium and 800 IU of vitamin D daily. 161 postmenopausal women with breast cancer participated; 110 came for their 6-month follow-up, and 71 came for their 1-year follow-up. At 6 months, bone loss was 1.3±3.2% on the spine, 1.7±3.9% on the femoral neck, 0.76±2.3% on the total hip, 1.2±3.4% on the trochanter, and 0.92±3.2% on the intertrochanter.