A 6-year-old boy with a rare condition called HDR syndrome that affects how his body handles calcium became dangerously sick twice from having too much calcium in his blood. Doctors discovered the problem wasn’t from his medicines alone—it was also from getting too much calcium from his special feeding tube formula. When doctors changed what he ate and gave him fluids, he got better. This case shows that doctors need to carefully check how much calcium kids with this condition are getting from their food and formula, not just from their medicines.
The Quick Take
- What they studied: Why a young child with a rare bone condition got dangerously high calcium levels in his blood twice, and how doctors figured out what caused it
- Who participated: One 6-year-old boy with HDR syndrome (a rare genetic condition affecting calcium control, hearing, and kidney development) who had trouble eating normally and needed a feeding tube
- Key finding: The boy’s dangerous calcium levels came from both his medicines AND too much calcium in his tube feeding formula. When doctors stopped giving him calcium supplements and switched his formula, his calcium levels returned to normal without changing his medicine dose.
- What it means for you: If you have a child with this rare condition or similar calcium-handling problems, doctors should check not just the medicines but also how much calcium is in their food and formula. This suggests that sometimes less medicine might work if the diet is managed carefully.
The Research Details
This is a case report, which means doctors are sharing the story of one patient’s experience to teach other doctors what they learned. The doctors carefully tracked one 6-year-old boy over 2 years, measuring his blood calcium levels, urine calcium levels, and kidney function. They looked at everything he was eating and drinking, including his special tube feeding formula, and compared it to his medicines to figure out what was causing his problems.
The doctors used standard blood tests and urine tests to measure calcium levels. They also looked at his medical history and what happened when they made changes to his diet and medicines. This type of detailed patient story is useful because it can show doctors something unexpected that might not show up in larger studies.
Case reports are important because they can reveal unexpected problems or solutions that doctors might miss. This case is especially important because it shows that doctors need to think about ALL sources of calcium, not just medicines. It also suggests a new way to help kids with this condition—using real blended food through the feeding tube instead of commercial formula, which might give more control over calcium intake.
This is a single case report, so it shows what happened to one child but cannot prove this happens to all children with this condition. However, the doctors carefully documented everything over 2 years, which makes the information reliable for this one patient. The findings are interesting enough that other doctors should pay attention and watch for similar situations in their own patients.
What the Results Show
The 6-year-old boy had two separate episodes of severe high calcium in his blood (hypercalcemia). Doctors initially thought his medicines were the problem and reduced them, but the calcium stayed high. When they looked more carefully at his diet, they discovered he was getting too much calcium from his tube feeding formula.
The key discovery was that when doctors tried to give him more formula to help him gain weight and get more calories, the extra formula also brought extra calcium. His body couldn’t handle all that calcium at once. Once doctors stopped giving him calcium supplements and switched him to a different feeding approach, his blood calcium and urine calcium levels both returned to normal within a few weeks.
Most importantly, after 2 years of follow-up, the boy stayed healthy with normal calcium levels while taking only calcitriol (a form of vitamin D) without any calcium supplements. This suggests his regular diet was providing enough calcium once the excess from the formula was removed.
The doctors also found that the boy’s kidneys were handling calcium better after the diet change. His urine calcium-to-creatinine ratio (a measure of how much calcium his kidneys were losing) normalized and stayed normal. This is important because too much calcium in urine can damage kidneys over time. The case also showed that switching to blenderized real food through the feeding tube instead of commercial formula gave doctors better control over calcium intake while still providing enough calories.
Previous cases of high calcium in children with this condition usually blamed medicine overdose. This case is different because it shows that dietary calcium can be just as important as medicine in causing problems. It also challenges the common practice of always giving calcium supplements along with vitamin D—suggesting that if diet provides enough calcium, supplements might not be needed.
This is only one child’s story, so we cannot know if this happens to other children with the same condition. The boy had feeding difficulties and was on a feeding tube, which is not true for all children with this condition. Results might be different for children eating regular food. Doctors would need to study more children to know how common this problem is and whether the same solution works for others.
The Bottom Line
For children with HDR syndrome or similar calcium-handling conditions: (1) Doctors should carefully measure how much calcium is in all sources—medicines, formula, and food—not just check the medicine dose. (2) When increasing formula volume for weight gain, doctors should check if this increases calcium too much. (3) Consider using blenderized real food through feeding tubes as an alternative to commercial formula to better control calcium intake. Confidence level: Low to moderate, based on one case, but important enough for doctors to consider.
Parents and doctors of children with HDR syndrome or other rare conditions affecting calcium control should pay attention to this case. Children with feeding tubes who take calcium-controlling medicines should have their calcium levels checked regularly. This is less relevant for children with normal calcium control or those eating regular food without supplements.
In this case, calcium levels returned to normal within weeks after diet changes. However, the long-term benefit (staying normal for 2 years) shows that the solution was lasting. If your child has similar issues, improvements might take several weeks to show up in blood tests.
Want to Apply This Research?
- Track daily calcium intake from all sources (medicines, formula, food) and compare it to blood calcium test results. Record the date, type of calcium source, estimated amount, and corresponding blood calcium level from doctor visits.
- If your child takes calcium medicines and uses a feeding tube, work with your doctor to create a calcium tracking log. When formula volume increases, ask your doctor to check calcium levels within 2-4 weeks. Consider discussing blenderized food options with your medical team as an alternative to commercial formula.
- Set monthly reminders to review calcium intake sources and blood test results. Track any symptoms like nausea, constipation, or increased thirst. Keep a log of formula changes and corresponding calcium level changes to share with your doctor at each visit.
This case report describes one child’s experience and should not be used to diagnose or treat any condition. If your child has hypoparathyroidism, HDR syndrome, or any condition affecting calcium levels, work closely with your child’s doctor before making any changes to medicines, diet, or feeding plans. High calcium levels can be serious and require medical supervision. Always consult with healthcare providers before adjusting calcium intake or medicines.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.