Vitamin D and hypophosphatemia in patients with anorexia nervosa and avoidant/restrictive food intake disorder: a case control study.

BACKGROUND: Refeeding hypophosphatemia (RH) is a common complication of nutritional restoration in malnourished individuals, yet clear risk stratification remains elusive. Individuals with anorexia nervosa (AN) and avoidant/restrictive food intake disorder (ARFID) may be deficient in vitamin D, an important component of dietary phosphorus absorption in the gut. The relationship between vitamin D and RH in AN and ARFID is unknown. Therefore, the aims of this study were to (1) report rates of low serum 25-hydroxy vitamin D and RH in AN and ARFID; (2) describe associations between phosphorus and variables associated with RH identified in extant literature; (3) examine the relationship between 25-hydroxy vitamin D and RH and (4) investigate moderation by vitamin D between variables of interest and phosphorus level. METHOD: Analyses included retrospective chart review of 307 individuals admitted to the ACUTE Center for Eating Disorders and Severe Malnutrition with a diagnosis of AN or ARFID. Variables of interest included admission laboratory values (vitamin D level, comprehensive metabolic panel, hemoglobin, point-of-care blood glucose), anthropometric measures (weight, body mass index [BMI], % ideal body weight [IBW]), age, duration of illness, length of stay, feeding method, and serum phosphorus nadir. Pearson and Spearman rank correlation, one-way ANOVA, and regression analyses were used to determine the relationship between variables and serum phosphorus. RESULTS: Over 1/3 of the sample (35.3%) had serum phosphorus levels ≤ 2.9 mg/dL. There were no significant differences between groups in phosphorus nadir (p = .17, η2 = 0.12) or hypophosphatemia (p = .16, ϕc = 0.11). Thirty-five (35%) of individuals with ARFID were either deficient or insufficient in vitamin D, compared to 29% of individuals with AN. Individuals with AN had significantly higher mean vitamin D levels compared to those with ARFID (p = .03; η2 = 0.015). Nadir phosphorus showed a positive association with weight, BMI, %IBW, potassium, and calcium on admission, and a negative association with length of stay, hemoglobin, and total number of tube-fed days. Higher levels of 25-hydroxy vitamin D moderated the relationship between serum phosphorus nadir and weight on admission (p = .0004). CONCLUSION: Individuals diagnosed with ARFID are as nutritionally fragile as those with AN regarding vitamin D and RH. The negative feedback loop involving vitamin D that maintains phosphorus homeostasis may play a role in the development of RH in AN and ARFID.

Refeeding hypophosphatemia (RH) is a common and potentially serious complication of nutrition restoration, yet its risk is not fully understood. Vitamin D is an important part of phosphorus absorption in the gut. We examined 25-hydroxy vitamin D levels on admission and the relationship with RH in individuals with avoidant/restrictive food intake disorder (ARFID) and anorexia nervosa (AN). Results showed individuals with ARFID had significantly lower vitamin D levels than individuals with restrictive type AN, but not individuals with binge/purge type AN. Additionally, analyses showed that higher levels of vitamin D may play a role in the association between RH and weight on admission. Better understanding of RH risk may improve care.

Vitamin D and Hypophosphatemia in Patients with Anorexia Nervosa and Avoidant/Restrictive Food Intake Disorder: A Case Control Study.

Background: Refeeding hypophosphatemia (RH) is a common complication of nutritional restoration in malnourished individuals, yet clear risk stratification remains elusive. Individuals with anorexia nervosa (AN) and avoidant/restrictive food intake disorder (ARFID) may be deficient in vitamin D, an important component of dietary phosphorus absorption in the gut. The relationship between vitamin D and RH in AN and ARFID is unknown. Therefore, the aims of this of this study were to 1) describe the prevalence of low serum 25-hydroxy vitamin D levels and RH in AN and ARFID 2) report associations between nadir phosphorus level and variables associated with RH in extant literature and 3) examine the relationship between 25-hydroxy vitamin D levels and serum phosphorus nadir in AN and ARFID. Method: Analyses included retrospective chart review of 307 individuals admitted to the ACUTE Center for Eating Disorders and Severe Malnutrition with a diagnosis of AN or ARFID. Variables of interest included admission laboratory values (vitamin D level, comprehensive metabolic panel, hemoglobin, point-of-care blood glucose), anthropometric measures (weight, body mass index [BMI], % ideal body weight [IBW]), age, duration of illness, length of stay, feeding method, and serum phosphorus nadir. Pearson and Spearman rank correlation, one-way ANOVA, and regression analyses were used to determine the relationship between variables and serum phosphorus. Results: Over 1/3 of the sample (35.3%) had serum phosphorus levels ≤ 2.9 mg/dL. There were no significant differences between groups in phosphorus nadir (p = .17, η2 = 0.12) or hypophosphatemia (p = .16, ϕc = 0.11); 44% of individuals with ARFID and 33% of individuals with AN had hypophosphatemia. Nadir phosphorus showed a positive association with weight, BMI, %IBW, potassium, and calcium on admission, and a negative association with length of stay, hemoglobin, and total number of tube-fed days. Higher levels of 25-hydroxy vitamin D moderated the relationship between serum phosphorus nadir and weight on admission (p = .0004). Conclusion: Individuals diagnosed with ARFID are as nutritionally fragile as those with AN regarding vitamin D and RH. The negative feedback loop involving vitamin D that maintains phosphorus homeostasis may play a role in the development of RH in AN and ARFID.

Renal and electrolyte complications in eating disorders: a comprehensive review.

Eating disorders are psychiatric disorders with significant and widespread medical complications, including renal disorders. Renal disease is not uncommon in patients with eating disorders but is often unrecognized. It includes both acute renal injury and progression to chronic kidney disease requiring dialysis. Electrolyte abnormalities including hyponatremia, hypokalemia, and metabolic alkalosis are common in eating disorders and vary depending on whether patients engage in purging behaviors. Chronic hypokalemia due to purging in patients with anorexia nervosa-binge purge subtype or bulimia nervosa can lead to hypokalemic nephropathy and chronic kidney disease. Additional electrolyte derangements are seen during refeeding, including hypophosphatemia, hypokalemia, and hypomagnesemia. Patients can also develop Pseudo-Bartter's syndrome which leads to edema and rapid weight gain in patients who cease purging behavior. Clinicians and patients should be aware of these complications in order to provide education and early detection and prevention.

Eating disorders are common and serious mental health disorders with frequent medical complications. This review discusses some of the problems with kidney function and electrolyte abnormalities that occur in patients with eating disorders. Common eating disorders discussed are anorexia nervosa and bulimia nervosa. Anorexia nervosa involves eating very small amounts of food and may include intentional vomiting or misuse of medications called laxatives or diuretics. These behaviors can cause decreased blood flow to the kidneys and subsequent kidney failure, as well as problems with important electrolytes in the body including potassium and sodium. These can lead to very serious problems, including death. Patients dealing with these issues should be seen by their doctor and potentially hospitalized for treatment.

A Comprehensive Review of Complications and New Findings Associated with Anorexia Nervosa.

Anorexia nervosa is a complex and deadly psychiatric disorder. It is characterized by a significant degree of both co-occurring psychiatric diseases and widespread physiological changes which affect nearly every organ system. It is important for clinicians to be aware of the varied consequences of this disorder. Given the high rate of mortality due to AN, there is a need for early recognition so that patients can be referred for appropriate medical and psychiatric care early in the course of the disorder. In this study, we present a comprehensive review of the recent literature describing medical findings commonly encountered in patients with AN. The varied and overlapping complications of AN affect pregnancy, psychological well-being, as well as bone, endocrine, gastrointestinal, cardiovascular, and pulmonary systems.