Doctors discovered an extremely unusual condition in a newborn baby where muscles started turning into bone—something that had never been reported before in such a young patient. The baby had kidney problems and low vitamin D levels, which appear to have triggered this rare bone-forming disease. After treatment with vitamin D supplements, the baby improved significantly and the muscle ossification gradually went away. This case is important because it shows doctors a new way that kidney disease and vitamin D deficiency can affect newborns, helping them recognize and treat similar cases in the future.

The Quick Take

  • What they studied: A single newborn baby who developed a rare condition where muscles were turning into bone, combined with kidney failure and vitamin D deficiency
  • Who participated: One extremely premature newborn admitted to intensive care who developed acute kidney injury in the first days of life
  • Key finding: This is the first-ever reported case of muscle ossification (bones forming in muscles) in a newborn caused by kidney disease and vitamin D deficiency. The condition improved completely after vitamin D treatment
  • What it means for you: If you have a newborn with kidney problems and vitamin D deficiency, doctors should watch for signs of muscle stiffness or swelling. This case shows that vitamin D treatment may help prevent or reverse this rare condition. However, this is based on one case, so more research is needed

The Research Details

This is a case report, which means doctors documented the medical history and treatment of one specific patient. The extremely premature newborn was admitted to the neonatal intensive care unit (NICU) and developed acute kidney injury early in life, along with very low vitamin D levels. The doctors used multiple imaging tests to diagnose the condition: regular X-rays showed bone formation in the muscles, CT scans provided detailed pictures, and bone scans revealed abnormal bone-building activity in the affected areas. The baby was treated with two forms of vitamin D (alfacalcidol and cholecalciferol) and monitored over time to see if the condition improved.

Case reports are important for identifying rare diseases that doctors may have never seen before. By documenting this unusual case in detail, the doctors are alerting other medical professionals worldwide to watch for similar patterns in their patients. This helps build medical knowledge about how kidney disease and vitamin D deficiency can affect newborns in unexpected ways

As a case report of a single patient, this study cannot prove cause-and-effect relationships or be applied broadly to all newborns. However, the diagnosis was confirmed using multiple imaging methods (X-rays, CT scans, and bone scans), which strengthens confidence in the findings. The doctors did not perform a muscle biopsy, but the symmetrical pattern of bone formation in both sides of the body made cancer unlikely. The main limitation is that we cannot know if other newborns would respond the same way to treatment

What the Results Show

This newborn developed a rare condition called myositis ossificans, where muscles in the hip and thigh area began turning into bone. This had never been reported before in a newborn and is extremely uncommon even in adults. The condition appeared to be directly related to two problems: the baby’s failing kidneys and severe vitamin D deficiency. When doctors treated the baby with vitamin D supplements (alfacalcidol and cholecalciferol), the baby’s kidney function improved, vitamin D levels normalized, and the muscle ossification gradually reversed. Follow-up imaging tests showed that the abnormal bone formation stopped and the baby’s condition continued to improve over time.

The imaging tests revealed important details about how the disease progressed. Initial X-rays and CT scans showed bone formation in specific muscles (iliopsoas, gluteus maximus, and thigh muscles). Bone scans showed that the body’s bone-building cells were working overtime in these areas. As treatment progressed, repeat bone scans confirmed that this abnormal activity decreased and the bone formation stopped. The symmetrical pattern of bone formation on both sides of the body helped doctors rule out cancer or other serious conditions

In adults with chronic kidney disease, doctors have documented cases where muscles turn into bone, and this is linked to mineral and bone problems caused by kidney failure. However, this is the first time this condition has been reported in a newborn. The case suggests that the same mechanism that causes this rare bone disease in adults can occur in newborns with kidney problems and vitamin D deficiency, though it appears to be even rarer in this age group

This study describes only one patient, so we cannot know if other newborns with similar conditions would respond the same way. The doctors did not perform a muscle biopsy to confirm the exact nature of the bone formation, though the imaging evidence was very clear. We don’t know if there are other newborns with this condition who were never diagnosed or reported. Long-term follow-up information beyond the initial treatment period is not provided, so we don’t know if the improvement continues indefinitely

The Bottom Line

For newborns with kidney failure and vitamin D deficiency: (1) Vitamin D supplementation appears helpful based on this case (moderate confidence—based on one patient); (2) Regular monitoring with imaging tests may help catch muscle ossification early if it develops (moderate confidence); (3) Doctors should be alert to signs of muscle stiffness or swelling in at-risk newborns (moderate confidence). These recommendations should be discussed with your neonatal care team

Parents of premature newborns with kidney problems should be aware of this rare possibility. Neonatal doctors and kidney specialists should consider this condition when treating newborns with combined kidney disease and vitamin D deficiency. This is not relevant to healthy newborns or those without kidney problems

In this case, clinical improvement began within weeks of starting vitamin D treatment, with gradual improvement over months. However, since this is a single case, the timeline may vary for other patients

Want to Apply This Research?

  • For parents of newborns with kidney disease: Track vitamin D levels (measured in blood tests) monthly, kidney function tests (creatinine and BUN) weekly initially then monthly, and note any signs of muscle stiffness, swelling, or reduced movement in arms and legs
  • Work closely with your neonatal team to ensure prescribed vitamin D supplements are given on schedule. Keep all imaging appointments (X-rays, ultrasounds, or scans) as recommended. Report any new muscle swelling, stiffness, or movement changes immediately to your doctor
  • Maintain a health log documenting: (1) Vitamin D supplement doses and dates given; (2) Lab test results for vitamin D and kidney function; (3) Any physical changes in the baby’s movement or muscle appearance; (4) Dates and results of imaging tests. Share this log with your medical team at each visit

This case report describes a single patient and cannot be applied to all newborns or used to diagnose conditions. If your newborn has kidney problems or vitamin D deficiency, work with your pediatric kidney specialist and neonatal care team for personalized medical advice. Do not start or stop any medications without consulting your doctor. This information is educational and not a substitute for professional medical diagnosis or treatment. Always seek immediate medical attention if your newborn shows signs of muscle swelling, stiffness, or movement problems.