Researchers studied 575 children with chronic kidney disease to understand which vitamins and minerals they weren’t getting enough of. They found that 9 out of 10 children weren’t getting enough vitamin D, and many were also low in vitamin E, iron, and folate. By looking at blood samples, scientists discovered that when children didn’t get enough of certain vitamins, it affected how their bodies processed fats and other important chemicals. This research helps doctors understand why children with kidney disease sometimes struggle with growth and development, and suggests that paying attention to nutrition might be really important for their health.

The Quick Take

  • What they studied: Whether children with chronic kidney disease were getting enough vitamins and minerals in their diet, and how this affected the chemicals in their blood.
  • Who participated: 575 children between 6 months and 16 years old with moderate kidney disease from across North America. About 4 out of 10 were girls, and on average they were 12 years old.
  • Key finding: Nine out of every 10 children with kidney disease weren’t getting enough vitamin D. More than 3 out of 4 weren’t getting enough vitamin E. When children didn’t eat enough of certain vitamins and minerals, it changed the levels of important fats and chemicals in their blood.
  • What it means for you: If your child has kidney disease, their doctor should check whether they’re getting enough vitamins and minerals, even if their weight looks normal. Better nutrition might help with growth and development, but talk to your child’s kidney doctor before making big dietary changes.

The Research Details

This was a long-term study that followed the same group of children over time. Researchers asked families about what the children ate using detailed food questionnaires at three different time points (at 6 months, 2 years, and 4 years into the study). They counted up how much of 15 different vitamins and minerals each child was getting from food. At those same time points, the researchers took blood samples and used special lab tests to measure hundreds of different chemicals in the blood. This allowed them to see if children who ate less of certain vitamins had different levels of chemicals in their blood.

The study focused on children with stage 2-4 chronic kidney disease, which means their kidneys weren’t working at full strength but weren’t completely failing. The researchers used statistical methods to figure out which vitamins and minerals were connected to which blood chemicals, while accounting for other factors that might affect the results.

This approach is powerful because it follows real children over time and looks at actual food intake rather than just guessing. It helps doctors understand the real-world connection between what kids eat and what happens in their bodies.

Understanding what vitamins and minerals children with kidney disease are missing is important because kidney disease can affect how the body absorbs and uses nutrients. By measuring the actual chemicals in the blood, researchers can see the real impact of poor nutrition on the body’s basic functions. This helps doctors know which nutrients to focus on when caring for children with kidney disease.

This study is reliable because it included a large number of children (575) and followed them over several years, which gives a clearer picture than a one-time snapshot. The researchers used detailed food questionnaires and advanced lab testing to measure nutrients and blood chemicals accurately. However, the study only describes what they found—it doesn’t prove that low vitamins actually cause the blood chemical changes, just that they’re connected. The results apply best to children with moderate kidney disease in North America.

What the Results Show

The most striking finding was that vitamin D deficiency was extremely common—90% of the children weren’t getting enough. This was followed by vitamin E deficiency in 77% of children. More than 45% of children weren’t getting enough iron or folate, which are important for making blood and energy.

Children whose kidneys were working worse (lower kidney function) tended to eat less zinc and B vitamins (B5 and B6). This suggests that as kidney disease gets more serious, nutrition problems may get worse too.

When researchers looked at the blood chemicals, they found that micronutrient intake was connected to 99 different chemicals in the blood. Vitamin D and B12 intake were especially connected to chemicals involved in fat metabolism—how the body breaks down and uses fats. Vitamin C showed the strongest connection to specific chemicals called stachydrine and 3-hydroxystachydrine.

The overall pattern showed that children with kidney disease who weren’t eating enough vitamins had changes in how their bodies processed fats and other important molecules, which could affect growth and development.

Iron, folate, and vitamins C, A, and K were connected to different types of blood chemicals than vitamin D and B12. These nutrients were linked to chemicals involved in breaking down foreign substances, using vitamins and minerals, and processing amino acids (the building blocks of protein). This suggests that different vitamins and minerals affect different body systems, so a well-rounded diet with many nutrients is important.

Previous research has shown that children with kidney disease often have poor growth and development, but the reasons weren’t completely clear. This study adds important information by showing that vitamin and mineral deficiencies are extremely common in these children and that these deficiencies are connected to real changes in how the body works at a chemical level. The findings support what doctors have suspected—that nutrition plays a big role in the health problems seen in children with kidney disease.

This study shows connections between vitamins eaten and blood chemicals, but it doesn’t prove that low vitamins actually cause the blood chemical changes. It’s like noticing that people who carry umbrellas are wet—you can’t tell if the umbrella caused the wetness or if they got wet first and then grabbed an umbrella. The study only looked at children with moderate kidney disease, so results might be different for children with milder or more severe kidney disease. Also, the researchers relied on families to remember what their children ate, which might not be perfectly accurate.

The Bottom Line

Children with chronic kidney disease should be checked regularly to see if they’re getting enough vitamins and minerals, especially vitamin D, vitamin E, iron, and folate. (Confidence: High—this is based on clear evidence of widespread deficiencies.) If deficiencies are found, doctors should consider whether supplements or dietary changes might help. (Confidence: Moderate—this study shows the problem exists but doesn’t prove that fixing it will help.) Any changes to diet or supplements should be made with the child’s kidney doctor because kidney disease can affect how the body handles nutrients.

This research is most important for children who have been diagnosed with chronic kidney disease and their families. Kidney doctors and dietitians who work with children with kidney disease should use this information to screen for vitamin and mineral deficiencies. Parents of children with kidney disease should ask their doctor about whether their child might need vitamin or mineral supplements. This research is less relevant for children with healthy kidneys.

Vitamin and mineral deficiencies develop over weeks to months, so checking levels every few months makes sense. If supplements are started, it may take several weeks to months to see changes in blood chemical levels. Improvements in growth and development might take even longer—usually several months to a year—so patience is important.

Want to Apply This Research?

  • Track daily intake of key nutrients (vitamin D, vitamin E, iron, folate, and B vitamins) using a food diary feature. Set daily goals based on dietary reference intake values and log foods eaten. Weekly summaries can show whether targets are being met.
  • Use the app to identify vitamin D-rich foods (fortified milk, fatty fish, egg yolks) and iron-rich foods (lean meat, beans, fortified cereals) that fit within kidney disease dietary restrictions. Create a shopping list of approved foods high in deficient nutrients. Set reminders to take prescribed supplements at the same time each day.
  • Log food intake daily and review weekly nutrient totals. Track any supplements taken. Share monthly summaries with the child’s kidney doctor and dietitian. Note any changes in energy, growth, or how the child feels. If blood work is done, record nutrient levels and compare to previous results to see if dietary changes are working.

This research describes patterns in how vitamins and minerals relate to blood chemistry in children with kidney disease, but it does not prove that vitamin deficiencies cause health problems or that supplements will fix them. Children with chronic kidney disease have special nutritional needs that differ from healthy children, and some nutrients must be carefully controlled because of kidney disease. Do not start, stop, or change any supplements or make major dietary changes without talking to your child’s kidney doctor or registered dietitian. This information is educational and should not replace professional medical advice. Always work with your child’s healthcare team when making decisions about nutrition and supplements.