What is the normal range of calcitonin (calcitonin) levels in children between 1 to 5 years old?

Normal Calcitonin Values in Children Ages 1-5

The normal range of calcitonin in children aged 1-5 years is gender-dependent, with significantly higher values in boys than girls, and shows an accelerated decline from infancy to approximately age 4-5 years for both sexes. 1

Age and Gender-Specific Reference Ranges

Calcitonin levels in children demonstrate clear age and gender dependencies that must be considered when interpreting results:

• Calcitonin levels are significantly higher in boys than girls (p<0.01) 1
• Both genders show an accelerated decline in calcitonin levels from infancy until approximately 4-5 years of age 1
• After age 5, the decline continues but at a slower rate

Clinical Interpretation Guidelines

When evaluating calcitonin levels in children aged 1-5:

• Use gender-specific reference ranges to properly interpret results
• Consider that calcitonin levels naturally decrease during this age period
• Be aware that using adult reference ranges can lead to misinterpretation of results

Factors Affecting Calcitonin Levels

Several factors can influence calcitonin measurements in children:

• Calcium levels (calcium is a primary secretagogue for calcitonin) 2
• Renal function (impaired kidney function can elevate calcitonin) 2
• Certain medications (e.g., β-blockers can affect results) 2
• Thyroid diseases (though these have minimal impact, affecting only about 1.5% of pediatric patients) 1

Clinical Applications

The primary clinical application for calcitonin measurement in children is screening for medullary thyroid carcinoma (MTC), particularly in those with:

• Multiple endocrine neoplasia type 2 (MEN 2)
• Family history of MTC
• RET proto-oncogene mutations

For children with high-risk RET mutations, the National Comprehensive Cancer Network and American Thyroid Association recommend prophylactic total thyroidectomy by age 5, regardless of calcitonin levels 3.

Measurement Considerations

• Use highly sensitive immunoassays specifically validated for pediatric populations
• The electrochemiluminescence immunoassay (ECLIA) has been validated in large pediatric cohorts 1
• Interpret results using age and gender-specific reference ranges
• Consider calcium stimulation testing for borderline results, though this is less commonly needed with modern sensitive assays

Common Pitfalls to Avoid

1. Using adult reference ranges for pediatric patients
2. Failing to account for gender differences in reference ranges
3. Not considering the natural decline in calcitonin levels during early childhood
4. Overlooking non-MTC causes of elevated calcitonin (renal insufficiency, certain medications)

The establishment of proper pediatric reference ranges from large cohorts of healthy children has significantly improved the laboratory monitoring of calcitonin in pediatric patients, particularly those with MEN 2 and suspected MTC 1.