Assessment and management of vitamin status in children with CKD stages 2-5, on dialysis and post-transplantation: clinical practice points from the Pediatric Renal Nutrition Taskforce.

Children with chronic kidney disease (CKD) are at risk for vitamin deficiency or excess. Vitamin status can be affected by diet, supplements, kidney function, medications, and dialysis. Little is known about vitamin requirements in CKD, leading to practice variation.The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric kidney dietitians and pediatric nephrologists, was established to develop evidence-based clinical practice points (CPPs) to address challenges and to serve as a resource for nutritional care. Questions were formulated using PICO (Patient, Intervention, Comparator, Outcomes), and literature searches undertaken to explore clinical practice from assessment to management of vitamin status in children with CKD stages 2-5, on dialysis and post-transplantation (CKD2-5D&T). The CPPs were developed and finalized using a Delphi consensus approach. We present six CPPs for vitamin management for children with CKD2-5D&T. We address assessment, intervention, and monitoring. We recommend avoiding supplementation of vitamin A and suggest water-soluble vitamin supplementation for those on dialysis. In the absence of evidence, a consistent structured approach to vitamin management that considers assessment and monitoring from dietary, physical, and biochemical viewpoints is needed. Careful consideration of the impact of accumulation, losses, comorbidities, and medications needs to be explored for the individual child and vitamin before supplementation can be considered. When supplementing, care needs to be taken not to over-prescribe. Research recommendations are suggested.

Elevated Whole-Blood Manganese Levels in Adult Patients Prescribed "Manganese-Free" Home Parenteral Nutrition.

BACKGROUND: Manganese toxicity can occur as a complication of home parenteral nutrition (HPN). Patients can present with Parkinson disease-like symptoms. Preparations of trace elements (TEs) in parenteral nutrition (PN) generally provide amounts in excess of requirements. Our previous review observed 60% of adult HPN patients had high whole-blood manganese levels. Multi-TE (MTE) solutions were subsequently removed from all HPN formulations in January 2015. The aim of this evaluation was to determine whole-blood concentrations of manganese in adult patients receiving HPN to establish whether levels are now maintained within the normal reference range. METHODS: A retrospective review of whole-blood manganese levels in all patients receiving HPN between January 2018 and January 2019 from 1 hospital site was carried out. RESULTS: 100 patients were included in the review (59 female and 41 male). Normal whole-blood manganese levels (73-219 nmol/L) were observed in 70% of patients and elevated levels (>219 nmol/L) in 30% of patients. In the patients with elevated levels, 57% had not received manganese supplementation for at least 1 year prior to manganese being measured. Markers of cholestasis were similar between the 2 groups. CONCLUSIONS: Incidence of elevated whole-blood manganese concentrations in patients receiving HPN decreased from 60% to 30% upon discontinued use of an MTE solution. Elevated levels remain a concern despite patients being prescribed "manganese-free" PN. Patients receive this TE in amounts adequate to meet requirements through contamination and dietary intake alone, suggesting additional parenteral supplementation of manganese is not required.

The relationship between plasma albumin, alkaline phosphatase and pyridoxal phosphate concentrations in plasma and red cells: Implications for assessing vitamin B6 status.

BACKGROUND: Plasma concentrations of most vitamins decrease as part of the systemic inflammatory response (SIR). Thus low plasma values do not necessarily indicate deficiency. Vitamin B6 status is usually assessed by measurement of pyridoxal phosphate (PLP) in plasma, although vitamin concentrations in blood cells tend to be better markers of cellular stores. In health, plasma PLP appears to be determined primarily by intake, its binding to albumin, and its hydrolysis by alkaline phosphatase (ALP). OBJECTIVE: To examine, using in vitro studies, the effect of albumin concentration and ALP activity on PLP concentration in plasma and red blood cells of healthy subjects (HS) and critically ill patients (CI). DESIGN: Heparin and EDTA (ALP inhibited) whole blood samples from HS (n = 8) and CI (n = 26) were incubated with PLP. Concentration of PLP in plasma and red cells was measured. Albumin and ALP levels were determined in plasma. RESULTS: In PLP incubated heparin samples, there was a strong direct relationship between albumin in the concentration range 10-44 g/L and increase in plasma PLP concentration (rs = 0.93, P < 0.001) and an inverse relationship with increase in red cell PLP concentration (rs = -0.90, P < 0.001). In contrast, ALP activity was inversely associated with increase in plasma PLP concentration (rs = -0.42; P = 0.013) and directly associated with red cell PLP concentration (rs = 0.49; P = 0.003). CONCLUSIONS: Plasma albumin concentration and to a lesser extent ALP activity influences PLP concentration in plasma and red cells. In conditions associated with low albumin (e.g. SIR) or altered ALP activity, red cell PLP measurements are more likely to be reliable than plasma measurements in differentiating true from apparent vitamin B6 deficiency and to guide vitamin B6 supplementation.