Falls are a major cause of injury and mortality, especially among older adults, and contribute substantial burden to patients, families, and health systems. The biologic rationale linking vitamin D to fall prevention includes its role in calcium and phosphorus regulation, bone health, and direct effects on skeletal muscle via the vitamin D receptor. Prior studies and trials of vitamin D supplementation have produced mixed results, with potential threshold effects such that benefits may be more apparent in people with baseline vitamin D deficiency. Despite this background, the relationship between measured serum 25(OH)D concentrations and contemporaneous clinical fall-risk assessment using tools such as the Morse Fall Scale (MFS) has not been well characterized in hospitalized rehabilitation populations. This study examined whether serum 25(OH)D concentration is independently associated with MFS-defined high fall risk in hospitalized adults.
This cross-sectional analysis was approved by the institutional ethics committee and included hospitalized patients screened between May 3 and December 13, 2022, with data accessed for research in August 2025. After initial exclusions for severe underlying disease, fractures, communication impairments, poor nutrition, current vitamin D or calcium supplementation, and refusals, and further exclusions for incomplete data or other prespecified reasons, 131 participants remained for analysis.
Demographic and clinical information were collected with a standardized questionnaire and included age, sex, BMI, alcohol use, smoking, hypertension, diabetes, and hyperlipidemia. Fall risk was assessed using the Morse Fall Scale, which classifies patients as low (0–24 points), moderate (25–44 points), or high (≥45 points) risk.
Venous blood samples were obtained on the morning of the second hospital day. Measured laboratory variables included serum 25(OH)D, neuron-specific enolase (NSE), homocysteine (Hcy), C-reactive protein (CRP), fasting blood glucose, and platelet count. Vitamin D status categories applied in the analysis were deficiency (<25 nmol/L), insufficiency (25 to <50 nmol/L), and sufficiency (≥50 nmol/L); the authors note that some guidance uses a higher sufficiency threshold (≥75 nmol/L) but the 50 nmol/L cutoff was used consistently here.
Statistical comparisons across MFS groups used ANOVA or Kruskal–Wallis tests for continuous variables and χ² or Fisher’s exact tests for categorical variables, as appropriate. Multivariable binary logistic regression modeled factors associated with high fall risk (high versus low/moderate), adjusting for serum 25(OH)D, age, sex, and BMI. Results are reported as odds ratios (ORs) with 95% confidence intervals (CIs); p<0.05 was considered significant.
Of 357 patients screened, 131 were included in the final cross-sectional sample after staged exclusions. According to MFS scores, 4 participants were low risk, 15 were moderate risk, and 112 were high risk. The distribution of serum 25(OH)D concentrations differed across the three fall-risk groups (p = 0.003), with the high-risk group exhibiting the lowest concentrations. The manuscript provides tabulated demographic and clinical characteristics by MFS group and a figure showing the distribution of serum 25(OH)D across low-, moderate-, and high-risk subgroups.
In multivariable logistic regression adjusted for age, sex, and BMI, each 1 nmol/L increase in serum 25(OH)D was associated with lower odds of being in the MFS high-risk group (adjusted OR 0.93, 95% CI 0.89–0.96; p < 0.001). Increasing age was independently associated with higher odds of high fall risk (adjusted OR 1.07 per year, 95% CI 1.02–1.13; p = 0.01). Sex was not independently associated with high fall risk in the adjusted model (p = 0.79).
Other laboratory measures (NSE, Hcy, CRP, glucose, platelet count) and additional subgroup details are reported in the article tables. The authors categorized vitamin D status using the prespecified thresholds and emphasize that their chosen sufficiency cutoff was ≥50 nmol/L.
In this hospitalized cohort, lower serum 25(OH)D concentrations and older age were independently associated with higher MFS-defined fall risk. The findings align with biologic mechanisms linking vitamin D to muscle function and balance via the vitamin D receptor in skeletal muscle. The authors note that prior supplementation trials have shown mixed results and that benefits of vitamin D may depend on baseline vitamin D status; large trials in vitamin D-replete populations have not consistently demonstrated fall prevention effects.
Because this analysis is cross-sectional, temporality cannot be established — low serum 25(OH)D may be a marker associated with higher fall risk, or low vitamin D could contribute causally to risk. The study excluded patients receiving current vitamin D or calcium supplementation and obtained blood samples early after admission to reduce confounding. Limitations include the cross-sectional design, the relatively small sample size, and the predominance of high-risk patients in this hospitalized sample. The authors recommend prospective studies to determine whether correcting vitamin D deficiency reduces subsequent falls and to clarify temporal relationships.
In this cross-sectional sample of hospitalized adults assessed with the Morse Fall Scale, lower serum 25(OH)D concentrations and older age were independently associated with classification as high fall risk. The authors call for prospective studies to establish temporality and to test whether vitamin D repletion reduces incident falls. Details on dosing, intervention, and longitudinal outcomes were not reported in this study and would require prospective trial designs.