Enteral Ca-Intake May Be Low and Affects Serum-PTH-Levels in Pre-school Children With Chronic Kidney Disease

Abstract

Treatment of chronic kidney disease (CKD) mineral bone disorder (MBD) is challenging in growing children due to the high amount of calcium needed for normal bone mineralization and the required dietary phosphate restriction, which often includes intake of calcium-rich products such as milk. Therefore, enteral calcium-intake (Ca-I) was calculated.Patients: We looked at pediatric CKD-Patients aged 0–6 years.Design: We used a retrospective analysis of Ca-I from dietary data collections. Ca-I below 60% or above 100% of the D-A-CH and the KDOQI reference values were considered as severe Ca deficiency or Ca overload, respectively.Results: We had 41 children, median age 1.1 (range 0-5.8) years, body weight 7.3 (2.4–19.9) kg, and length 68 (48-105) cm at the time of first dietary data collection. Renal function was classified as CKD stage III in 20, IV in 28, V in 44, and VD in 142 dietary data collections. At the first dietary data collection, 5 children were in the CKD stage III, 10 in IV, 9 in V, and 17 were on dialysis. Only one child progressed to a higher CKD stage. In total, 234 dietary data collections were analyzed, and 65 follow-up collections were available from 33 children after a time interval of 26 (1–372) days. The median caloric intake was 120 (47–217)% of D-A-CH RDI. In 149 (63.6%) of the dietary data collections, enteral Ca-I was below the target (<100% of the D-A-CH and KDOQI RDI). Severe Ca-deficiency was found in 11 (26%) and 4 (12%) of the children at the first and second dietary data collection, respectively. In total, 11 children were on Ca-containing phosphate binders. In dietary data collection 1 and 2, there were seven children. From these, 4/7 and 4/7 patients had an enteral total Ca-I above the 100% D-A-CH-limit or above the KDOQI limit, respectively. Absolute dietary Ca-I and Ca-I normalized to body weight correlated negatively with PTH (r = −0.196, p < 0.005 and r = −0.13, p < 0.05).Conclusion: Enteral Ca-I should repeatedly be monitored in CKD children because many may may otherwise be underexposed to enteral calcium and overexposed when calcium-containing phosphate binders are given. Our findings suggest a major impact of dietary calcium supply on bone health in pediatric CKD.

Safety and Efficacy of Cinacalcet in Children Aged Under 3 Years on Maintenance Dialysis

“… 4 , 6 Recent observational studies, however, yielded lower dietary calcium intake in the majority of children with CKD 3 to 5D and an inverse correlation with serum PTH. 10 , 11 However, when considering calcium from medications, 41% of the children exceeded 200% of the recommended intake, 11 whereas in our cohort 14 children received less than 100% of daily RNI for calcium at cinacalcet introduction. In clinical routine, calcium supply is difficult to assess and provides rough estimates only.…”

“…High nutritional calcium supply is crucial, 8 but often difficult to achieve in clinical practice, especially in children on a phosphate restricted diet. 9 , 10 , 11 Even with optimized treatment, insufficient MBD control is prevalent, with significant obstacle to bone strength and cardiovascular disease worsening. 12 , 13 , 14 , 15 , 16 , 17 Conversely, the number of small children requiring dialysis is increasing globally, 13 , 18 because kidney replacement therapy has been widely accepted in otherwise stable children from the first days of life onwards.…”

Diagnosis and management of mineral and bone disorders in infants with CKD: clinical practice points from the ESPN CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce

“…Rationale A dietary assessment of infants with CKD should include energy, protein, and micronutrients aiming for the SDIs for calcium and phosphate, as outlined in previous recommendations [7,10,[73][74][75] from the PRNT and illustrated in Table 5 [7]. A specialist pediatric kidney dietitian or healthcare professional who has the necessary skills and training should carry out the dietary assessment [76].…”

“…An upper limit for Ca intake for healthy children of different ages has not been defined; however, 200% of the SDIs has been suggested as a safe upper limit for Ca intake from diet and phosphate binders in CKD [ 7 , 47 ]. Of note, the Ca intake from the diet may not provide sufficient Ca [ 74 ], particularly as most Ca-rich foods also contain large amounts of P, and are likely to be restricted in CKD patients [ 77 ]. In some situations, such as during periods of rapid catch-up growth, when there is a late presentation with untreated CKD, or in infants on daily hemodialysis, greater Ca intake than the SDI may be required [ 24 , 78 ].…”