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Practical Nutrition Management of Children with
Chronic Kidney Disease
Lieuko Nguyen, Rayna Levitt and Robert H. Mak
Division of Nephrology, Department of Pediatrics, Rady Children’s Hospital San Diego, University of California, San Diego, La Jolla, CA, USA.
ABSTR ACT: Chronic kidney disease (CKD) introduces a unique set of nutritional challenges for the growing and developing child. This article addresses
initial evaluation and ongoing assessment of a child with CKD. It aims to provide an overview of nutritional challenges unique to a pediatric patient with
CKD and practical management guidelines. Caloric assessment in children with CKD is critical as many factors contribute to poor caloric intake. Tube
feeding is a practical option to provide the required calories and fluid in children who have difficulty with adequate oral intake. Protein intake should not be
limited and should be further adjusted for protein loss with dialysis. Supplementation or restriction of sodium is patient specific. Urine output, fluid status,
and modality of dialysis are factors that influence sodium balance. Hyperkalemia poses a significant cardiac risk, and potassium is closely monitored. In
addition to a low potassium diet, potassium binders may be prescribed to reduce potassium load from oral intake. Phosphorus and calcium play a significant
role in cardiovascular and bone health. Phosphorus binders have helped children and families manage phosphorus levels in conjunction with a phosphorusrestricted diet. Nutritional management of children with CKD is a challenge that requires continuous reassessment and readjustment as the child ages,
CKD progresses, and urine output decreases.
KEY WORDS: children, chronic kidney disease, nutrition
CITATION: Nguyen et al. Practical Nutrition Management of Children with
Chronic Kidney Disease. Clinical Medicine Insights: Urology 2016:9 1–6
doi:10.4137/CMU.S13180.
COPYRIGHT: © the authors, publisher and licensee Libertas Academica Limited.
This is an open-access article distributed under the terms of the Creative Commons
CC-BY-NC 3.0 License.
TYPE: Review
CORRESPONDENCE: [email protected]
RECEIVED: December 2, 2014. RESUBMITTED: August 2, 2015. ACCEPTED FOR
PUBLICATION: December 14, 2015.
PEER REVIEW: Five peer reviewers contributed to the peer review report. Reviewers’
reports totaled 571 words, excluding any confidential comments to the academic
editor.
Paper subject to independent expert blind peer review. All editorial decisions made
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FUNDING: Authors disclose no external funding sources.
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Published by Libertas Academica. Learn more about this journal.
ACADEMIC EDITOR: Xiangyi Lu, Editor in Chief
The “Renal” Diet
In children with chronic kidney disease (CKD), there is no
one-size-fits-all diet that can be prescribed. Medical nutrition
therapy needs to be individualized and adjusted as the needs
change in a growing child, progression of CKD, and initiation and modality of dialysis. Considerations include calories, protein, sodium, potassium, calcium, phosphorus, and
iron. Initial assessment provides a starting point. Frequent
monitoring and reassessment allows the medical team, which
should include a renal dietitian, to adjust nutritional goals to
meet the changing needs of the child with different stages and
presentations of CKD.
Initial Evaluation
The initial evaluation of a child with renal disease includes
height, weight, head circumference (up to 36 months of age),
and body mass index.1 These parameters should be plotted
on the appropriate percentile charts. In children, serial measurements are required to properly assess growth. When plotting values, age should be adjusted for prematurity. In the
United States, Kidney Disease Outcomes Quality Initiative
(KDOQI) guidelines recommend the growth charts of World
Health Organization to monitor children at the age of 0 and
2 years and the growth charts of Centers for Disease Control
and Prevention to monitor children at the age of 2 years
and older. Disease-specific growth charts (eg, Trisomy 21,
Williams syndrome) can also be used when appropriate.
Calories, Formula, and Supplements
Per KDOQI 2008 guidelines, the energy needs of a child with
renal disease are expected to be the same as those of a healthy
child of the same age.2 Estimated needs can be adjusted
depending on growth and weight gain trends. Nausea, vomiting, gastroesophageal reflux, oral aversion, delayed gastric
emptying, renal tubular acidosis, elevation of cytokine levels,
and changes in leptin and ghrelin hormones all affect appetite
and contribute to inadequate caloric intake.
In infants, breast milk is the feeding of choice. If breast
milk is not available, standard infant formula may be appropriate. When a low potassium and/or low phosphorus intake
is required, Similac PM 60/40 can be offered. The choice
of formula takes into account the need for a low renal solute load. Formulas such as Similac PM 60/40® (Abbott
Laboratories) contain lower potassium and phosphorus
than standard infant formulas. Breast milk or formula may
be supplemented with glucose polymers, fats, and carbohydrates to increase caloric density. Concentrating the formulas by increasing the ratio of formula powder to water is not
Clinical Medicine Insights: Urology 2016:9
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Nguyen et al
recommended as it also increases electrolytes, which may be
dangerous in the face of a sodium-, potassium-, and phosphorus-restricted diet.
For older children, commercially prepared formula
nutritional supplements can be considered. There are currently no commercially available pediatric renal formulas for
children older than one year. Potential options for supplementation that are currently used include pediatric nonrenal
supplements such as Nestle Nutrition’s Compleat Pediatric®,
Nutren Junior®, Boost Kid Essentials®, and Abbott Nutrition’s PediaSure®, and adult renal formulas such as Abbott
Nutrition’s Nepro® and Suplena®, Nestle Nutrition’s NovaSource Renal®, and Renalcal®. Serum electrolytes should be
closely monitored when any supplementation is used. 3
Tube Feeding
Children born with CKD may develop oral aversion and
may not be able to take in sufficient calories for growth. Tube
feeding should be considered in these children as nutrition
is extremely important for physical and neurodevelopmental
growth. Some children will start with nasogastric (NG) feeding to supplement oral intake. However, dependence on NG
feeds to achieve adequate fluid, caloric, and protein intake
should prompt the medical team to consider gastrostomy tube
(G-tube) placement.4,5 Gastrostomy placement approaches
include percutaneous endoscopic gastrostomy versus laparoscopic versus open gastrostomy with or without Nissen fundoplication. Some patients may have difficulty in tolerating
gastric feeding volumes and may require gastrojejunostomy or
jejunostomy tube placement. Special consideration is given to
patients requiring peritoneal dialysis (PD) and G-tube placement. Complications including tube blockage, leakage around
exit site, exit site infection, gastrointestinal bleed, peritonitis,
the need for PD catheter replacement secondary to infection,
and the need for G-tube replacement have been reported.6,7
It is recommended that tube placement occurs before or concomitant with tunneled PD catheter placement to minimize
the risk of peritonitis. If G-tube placement occurs after PD
catheter placement, avoid using the PD catheter for two
Age
to three days and administer prophylactic antibiotics and
antifungals.8
Depending on the appetite and oral feeding skills of the
child, G-tube feeds can be used to supplement oral intake or
they may provide the soul source of nutrition. Tube feeds can
either be delivered by bolus or as continuous feeds. Higher
volumes required with bolus feeds may be poorly tolerated,
resulting in retching and vomiting. Potential aspiration risk
with gastroesophageal reflux is a concern with continuous
overnight feeds in infants in supine positions. Continuous
nighttime feeds for older children may be beneficial to promote daytime hunger and encourage oral intake.
Protein
The current KDOQI guidelines recommend providing
100%–140% of dietary reference intake (DRI) of protein for
ideal body weight for children with CKD stage 3. Children
with CKD stages 4 and 5 require 100%–120% of DRI for
ideal body weight. Children on dialysis should receive 100%
of DRI of protein for ideal body weight in addition to losses
from hemodialysis or PD. For patients on hemodialysis, an
estimated additional 0.1 g/kg/day of protein is required. For
patients on PD, an estimated additional 0.2–0.3 g/kg/day may
be required.
Figure 1 is from “KDOQI Clinical Practice Guideline
for Nutrition in Children with CKD: 2008 Update,” which
provides guidelines on recommended dietary protein intake in
children with CKD.2
Sodium
Children with advanced CKD who have poor urine output
typically require a sodium-restricted diet. A no-added-salt
diet that encourages cooking without salt is a starting point.
Teaching families and patients how to read nutrition labels
helps them to better assess their salt intake. KDOQI guidelines recommend ,1500–2400 mg/day for children who
require sodium restriction. Table 1 provides some practical
suggestions for patients requiring a sodium-restricted diet.
Children with salt wasting may require supplemental sodium.
DRI
DRI (g/kg/d)
Recommended for
CKD Stage 3 (g/kg/d)
(100%–140% DRI)
Recommended for CKD
Stages 4–5 (g/kg/d)
(100%–120% DRI)
Recommended
for HD (g/kg/d)*
Recommended
for PD (g/kg/d)†
0–6 mo
1.5
1.5–2.1
1.5–1.8
1.6
1.8
7–12 mo
1.2
1.2–1.7
1.2–1.5
1.3
1.5
1–3 y
1.05
1.05–1.5
1.05–1.25
1.15
1.3
4–13 y
0.95
0.95–1.35
0.95–1.15
1.05
1.1
14–18 y
0.85
0.85–1.2
0.85–1.05
0.95
1.0
Figure 1. Recommended dietary protein intake in children with CKD stages 3 to 5 and 5D. Reprinted with permission from: National Kidney Foundation
Kidney Disease Outcomes Quality Initiative. KDOQI clinical practice guideline for nutrition in children with CKD: 2008. Am J Kidney Dis. 2009;53(3):S1–S124.
Notes: *DRI + 0.1 g/kg/d to compensate for dialytic losses. †DRI + 0.15–0.3 g/kg/d depending on patient age to compensate for peritoneal losses.
2
Clinical Medicine Insights: Urology 2016:9
Pediatric chronic kidney disease
Table 1. Discussion points to help children lower their sodium intake.
Offer infants low-sodium finger foods when introducing solids.
Limit or avoid use of salt in cooking.
Do not add salt at the table.
Rely on fresh rather than processed foods.
Read food labels to Identify sodium content of foods.
Salty foods are defined as having more than 140 to 200 mg
(6 to 9 mmol) of sodium per serving.
Salt substitutes replace sodium chloride with potassium chloride
and are not suitable for children with hyperkalemia.
Add flavor to foods using spices, herbs, lemon or lime juice,
and vinegar.
Modify recipes to lower the sodium content, or look for renal or
low-sodium cookbooks.
Do not drink or use water from a water-softening system that
replaces hard minerals with sodium.
Enjoy home cooked meals and avoid high sodium fast food items.
Obtain nutrient content information from restaurants to choose
lower sodium foods.
Plan ahead for special occasions; pack low-salt snacks for outings.
Avoid foods that are high in sodium, including: soy sauce,
luncheon meat, ham, bacon, sausage, pepperoni, hot dogs,
processed cheese slices, string cheese, cheese spreads, packaged seasoning blends, pickles, ketchup, salted crackers, potato
chips, nacho chips, other salted snack foods, and dried soup mixes.
Choose lower sodium foods such as fresh meats and poultry,
homemade hamburgers, cream cheese, goat cheese, salt-free
crackers, unsalted chips, peanuts, and popcorn.
Children on PD with increased sodium losses in their ultrafiltrate may also require sodium supplementation.
Potassium
Hyperkalemia poses a more significant risk than hypokalemia in
children with CKD, increasing risks of arrhythmias and cardiac
arrest. KDOQI recommends a restriction of 40–120 mg/kg/
day for infants and younger children and 30–40 mg/kg/day
for older children.2 Breast milk has low potassium content and
should be encouraged for infants. Families should be educated
about high potassium foods to avoid. Salt substitutes that contain potassium should be avoided as well. The Food and Drug
Administration recently proposed changes to add potassium
content to nutrition labels, which often do not list potassium.
Table 2 provides some practical suggestions for patients requiring a potassium-restricted diet.
Potassium binders, such as sodium polystyrene sulfonate,
can be used to pretreat formulas to lower the potassium content. The medication is mixed with the formula and allowed to
form a precipitate. The supernatant is then decanted and used
to feed the child. For older patients, oral sodium polystyrene
sulfonate may be prescribed to lower serum potassium levels
if diet restrictions alone are not effective. Sodium polystyrene
sulfonate is a cation-exchange resin that can be administered orally or rectally as an enema. Approximately 1 mEq of
potassium in the gastrointestinal tract is exchanged per gram
Table 2. Discussion points to help children lower their potassium intake.
Encourage breast milk whenever possible as it is naturally low in potassium.
If breast milk is not available, offer an infant formula with a lower potassium content. Adult renal formulas may also be used in young children
to provide adequate calories with lower potassium content (Hobbs/Gast et al 2010).
If necessary, pre-treat infant formula or enteral feedings with a potassium binder to lower the potassium
content by approximately 50%.
The potassium content of commercial baby foods differs from the equivalent table food
(e.g., jarred, strained bananas versus fresh bananas).
A food is defined as being high in potassium if it contains more than 200 mg per serving.
Potassium in food cannot be tasted, and its content is infrequently listed on food labels.
Many fruits and vegetables are high in potassium.
Fruit drinks, beverages, punches, and soft drinks contain little or no potassium compared to fruit juices.
Peeling, dicing, and presoaking potassium-rich vegetables such as potatoes lowers their potassium content. The potassium content of root
vegetables can be reduced if the vegetables are peeled, diced and then soaked in water. The water should be discarded before preparing the
vegetables.
Cooking vegetables in water (i.e., boiling) lowers their potassium content, whereas other methods of cooking (i.e., microwaving, steaming,
deep frying, baking, roasting) do not.
Do not drink or use water from a water-softening system that replaces hard minerals with potassium.
Review serving sizes—a large serving of a low potassium food can turn it into a high source of potassium.
Avoid salt substitutes that contain potassium in place of sodium.
Avoid foods that are high in potassium, including bananas, oranges and orange juice, mangoes, papayas, dried fruits, baked potatoes,
french fries, potato chips, tomato products and chocolate.
Choose foods that are lower in potassium, such as apples, grapes, cherries, berries, cranberry juice, white rice, onion rings, popcorn,
pretzels, corn chips, cream sauces, and sugar candies without chocolate, nuts, or raisins.
Clinical Medicine Insights: Urology 2016:9
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Nguyen et al
sodium polystyrene sulfonate. In exchange for potassium,
4.1 mEq (∼100 mg) of sodium per gram of the drug is delivered, which may need to be added to total daily sodium intake
calculations. Sodium polystyrene sulfonate is not a fast-acting medication and should not be used as a sole therapy in
the management of acute moderate-to-severe hyperkalemia.
Sodium polystyrene sulfonate causes significant diarrhea at
the time of use. Fluid loss from diarrhea should be included
in total daily fluid losses with potential fluid replacement if
required. Small amounts of magnesium and calcium may also
be removed. Patients should be monitored for potential risk
of colonic necrosis even with sorbitol-free sodium polystyrene
sulfonate.9
Phosphorus
Hyperphosphatemia or hyperparathyroidism may necessitate
a dietary phosphorus restriction, which is often challenging for children. Hyperphosphatemia is an independent risk
factor that increases cardiovascular morbidity and mortality
such as vascular calcifications in patients with CKD and end
stage renal disease (ESRD) on dialysis.10,11 Poor bone health
affects linear growth as well.12 Management of hyperphosphatemia is therefore key in improving these outcomes. Limiting
phosphorus intake can help improve metabolic bone disease
and cardiovascular morbidity and mortality associated with
CKD. In the setting of elevated parathyroid hormone (PTH),
KDOQI guidelines recommend limiting phosphorus intake
to 100% of DRI for age. If serum phosphorus and serum PTH
levels are both elevated, it is recommended that phosphorus
intake be limited to 80% of the DRI. Phosphorus binders
may be prescribed in conjunction with a dietary phosphorus
restriction to help control serum phosphate levels. In children,
calcium carbonate, calcium acetate, and sevelamer carbonate
are the typical choices. These should be administered at the
time of food consumption and will bind with dietary phosphorus to prevent absorption. When choosing which phosphate binder to prescribe, one must consider dietary calcium
intake as well as the calcium content of the binder. Calciumcontaining binders should be carefully considered as they are
associated with the development of calcification. More calcium is absorbed from calcium carbonate when compared with
calcium acetate.13 Table 3 provides some practical suggestions
for patients requiring a phosphorus-restricted diet.
Calcium
Calcium balance is important to promote bone health and
mineralization. The current KDOQI recommendations suggest that total calcium intake should be between 100% and
200% of the DRI for age with a maximum of 2500 mg of
elemental calcium per day in older children. The total calcium
intake calculated should include the calcium-based phosphate
binders. Calcium supplementation may be necessary if dietary
intake does not meet DRI. Calcium gluconate, lactate, acetate,
and carbonate are the most effective forms of supplementation.
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Clinical Medicine Insights: Urology 2016:9
Table 3. Strategies for lowering dietary phosphorus intake and/or
absorption in infants and children.
Encourage breast milk whenever possible as it is naturally low in
phosphorus.
If breast milk is not available, use a low-phosphorus infant formula.
Use of this may be continued beyond 1 year of age to delay the
introduction of phosphorus-rich cow’s milk.
Fresh or frozen breast milk can be safely pretreated with sevelamer
to markedly reduce its phosphorus content without significantly
changing its content, with the exception of calcium and protein.3
Limit foods that are naturally high in phosphorus such as milk,
yogurt, cheese, organ meats, dried beans and peas, nuts and
nut butters, chocolate, quick breads, and whole-grain or bran
products.
Read labels to avoid foods and drinks with phosphate
containing additives. Examples of such products are processed
foods, carbonated beverages (colas), and canned ice tea or
juice drinks.
Rice milk may be used as a substitute for milk as long as it has not
been enriched with phosphate additives.
Time the delivery of phosphate binders so that it coincides with the
times during the day or night when the largest amounts of phosphorous is consumed (e.g., with overnight tube feeding).
Children and caregivers can be taught to adjust binders according
to the phosphate content of meals.
Calcium chloride may cause or worsen metabolic acidosis. 2
Calcium citrate can increase intestinal absorption of aluminum, leading to aluminum toxicity in CKD patients.14 The
addition of vitamin D supplementation increases intestinal
absorption of calcium.
Patients should be monitored for hypercalcemia as this
could increase the risk for calcification and cardiovascular diseases. Hemodialysis and PD can be modified with lower dialysate calcium concentrations. The most recent meta-analysis
does not show significant differences between paricalcitol or
calcitriol used in the treatment of secondary hyperparathyroidism in causing hypercalcemia.15 Calcimimetics such as
cinacalcet hydrochloride are considered to treat secondary
hyperparathyroidism in patients with hypercalcemia.
Iron
Anemia can be found in the early stages of CKD (as early
as CKD stage 2) and is secondary to loss of erythropoietin
production. In addition, many patients are found to be iron
deficient as well. Ongoing research on the role of hepcidin
in iron metabolism and subclinical inflammation as part of
the pathomechanism of anemia in CKD.16,17 Individual needs
such as age- and sex-specific hemoglobin distribution, neurocognitive development, and exercise capacity are considered
when targeting hemoglobin in children with CKD between
11 and 12 g/dL.18
The treatment of anemia in CKD begins with the full
evaluation of a child’s current iron status with the measurement of iron level, ferritin, and iron saturation. Supplemental
oral or intravenous iron is usually required by children of all
ages on erythropoietin-stimulating agents to avoid storage
Pediatric chronic kidney disease
iron depletion, prevent iron-deficient erythropoiesis, and
achieve and maintain target hemoglobin concentrations. Iron
supplementation can be provided in liquid formulation as well
for GT-dependent children. The starting dose recommendation is 3–4 mg/kg/day of elemental iron.18 KDIGO 2012
recommends the evaluation of iron status at least every three
months.
Vitamin B12 and Folate
Children with CKD and ESRD on dialysis can develop vitamin and mineral deficiencies due to anorexia, poor intake,
dietary restrictions, abnormal renal metabolism, drug–
nutrient interactions, poor gastrointestinal absorption, and
potential losses due to dialysis.19,20 In addition to iron supplementation, some children require vitamin B12 and folic acid
supplementation as part of the management of their anemia
of CKD. Canepa et al estimated the prevalence of hyperhomocysteinemia in up to 40% in children with chronic renal
failure.21 A small percentage of children with hyperhomocysteinemia have been found to have low folic acid levels and a
smaller percentage have been found to have low vitamin B12
levels.21 Elias et al reported an association between hyperhomocysteinemia and arterial stiffness in those with CKD
compared to those without CKD.22 However, a recent metaanalysis did not find that folic acid supplementation reduced
cardiovascular events in adults with kidney diseases.23 Due to
lack of supportive evidence, KDIGO 2012 does not support
folic acid supplementation as an adjuvant for ESA treatment.18
However, current practice provides folic acid and vitamin B12
to pediatric dialysis patients as part of a standard water-soluble
vitamin supplement.
Post-renal Transplantation
With a well functioning graft, the nutrition goals post-kidney
transplant shift. While the primary goal remains the optimization of nutrition status with adequate calories and protein,
there is a new focus on maximizing hydration while minimizing nutrition-related side effects of transplant medications.
The continued involvement of a renal dietitian is critical.
The target goal for caloric intake is 100% of energy efficiency ratio (EER) for age, adjusted for activity, and body size.
Protein needs increase after surgery to permit wound healing but return back to 100% of the DRI once healing is complete. Significant weight gain is often seen with prednisone
immunosuppression, 24 and excessive caloric consumption
becomes a prominent focus of discussion with encouragement of heart-healthy eating habits and increased physical
activity. New-onset diabetes after transplantation requires
further adjustment of the nutrition care plan with blood glucose monitoring and diabetic diet education. GT-dependent
children, particularly those with normal cognition, may show
a quick improvement of oral food intake after transplantation with the goal of transition off of G-tube feeds as soon as
they are able.25 Electrolyte imbalances such as hyperkalemia,
hypomagnesemia, and hypophosphatemia are often seen and
can be managed through dietary changes and medication
adjustments. These are usually secondary to medication effects
as well as the presence of secondary hyperparathyroidism
prior to transplant.
Summary
Nutritional management of children with CKD is a challenge
that requires continuous assessment and adjustment of the
nutrition care plan as the child ages and CKD progresses.
A renal dietitian plays a vital role in the multidisciplinary
approach to CKD management. Achieving a balance between
calorie, protein, and electrolyte needs can be challenging
in the face of multiple dietary restrictions, but with education
and support, it is possible to promote growth and weight gain
in children with CKD.
Author Contributions
Conceived the concepts: LN, RHM. Analyzed the data: LN,
RL, RHM. Wrote the first draft of the manuscript: LN. Contributed to the writing of the manuscript: LN, RL, RHM.
Agree with manuscript results and conclusions: LN, RL,
RHM. Jointly developed the structure and arguments for the
paper: LN, RHM. Made critical revisions and approved final
version: LN, RL, RHM. All authors reviewed and approved
of the final manuscript.
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