Vitamin D supplementation after malnutrition associated with time-related increase of cancer diagnoses: A cohort study of 389 patients with Wernicke-Korsakoff syndrome.

OBJECTIVES: Vitamin deficiencies may reflect less-than-optimal health in select populations. The aim of this study was to determine whether vitamin D supplementation (VDs) after malnutrition may be adversely related to cancer diagnoses in a selected group of patients with alcoholic Wernicke-Korsakoff syndrome (WKS).

METHOD: This was a retrospective cohort study of all patients admitted to Slingedael Korsakoff Center, from 1996 to 2018. The patients were subdivided into three predefined groups depending on differences in VDs: "early" supplementation, which started during or before the previous hospital admission, before the transfer to our center; "late" supplementation, which started later in our center; and "no" VDs received. Data collection involved patients' ages, sex, body mass index, skin type, baseline serum 25-hydroxyvitamin D concentrations if available, doses of cholecalciferol (vitamin D3 ) supplementation, other vitamins, sun exposure, malnutrition, alcohol use, smoking, cognitive diagnoses, somatic comorbidity, cancer diagnoses, cause of death, and length of stay in Slingedael. New tumors (dependent variable) may have been diagnosed during VDs (exposed cases) or before the start of VDs, if any (unexposed cases).

RESULTS: New cancers were diagnosed in 87 of 389 (22.4%) patients after median 3 y of follow-up (interquartile range, 1.1‒5.8 y). In logistic regression analysis, age, smoking, and length of stay in log (y) showed odds ratios of 1.021, 2.74, and 1.68, respectively. The temporal relationship of VDs and cancer diagnosis was significant in VDs that started in the year leading up to the diagnosis (Wilcoxon signed-ranks test of positive ranks corresponding with supplementation and negative ranks corresponding with non-supplementation: Z score 2.54; P = 0.011).

CONCLUSION: VDs was time-related to cancer diagnosis in a cohort of patients with alcoholic WKS. The study may suggest the proliferation of cancer as an adverse effect of VDs, particularly in malnourished patients.