# Marked Biological Variance in Endocrine and Biochemical Markers in Childhood: Establishment of Pediatric Reference Intervals Using Healthy Community Children from the CALIPER Cohort
Canonical: https://nutritionizm.com/research/10-1373-clinchem-2013-204222/
Last verified: 2026-10-26
Source: Clinical Chemistry (2013), DOI: https://doi.org/10.1373/clinchem.2013.204222
License: USDA FoodData Central values are public domain (CC0 1.0); Nutritionizm compilation and plain-language text are licensed under CC BY 4.0 (attribution: link to Canonical URL).

## TL;DR

Researchers created new normal blood test ranges for healthy children, including levels for nutrients like vitamin B12 and vitamin D.

## What they did

The researchers collected 1482 blood samples from healthy children between 2 days and 18 years old. They tested these samples on a laboratory analyzer. They looked at how age, sex, and ethnic background affected normal test levels.

## What they found

The team created normal test ranges for 14 biomarkers, including vitamin B12, vitamin D, and ferritin. They set the normal ranges using the 2.5th and 97.5th percentiles. They also found significant differences between ethnic groups for markers like cobalamin and vitamin D.

## Why it matters

Knowing normal blood levels helps doctors see if children are getting enough key nutrients. Studies suggest that healthy nutrient levels may vary based on a child's age and background. This information may help families and doctors better understand lab results when checking a child's diet.

## Limits

The authors noted that these ranges need more testing on other lab machines and in local groups of children. This is general education, not medical advice.

## Jargon explained

- **Reference intervals**: The range of normal test numbers usually seen in healthy people.
- **Biomarkers**: Measurable substances in the blood that show how the body is working.

## Full citation

Dana Bailey, David Colantonio, Lianna G. Kyriakopoulou, Ashley H. Cohen, Man Khun Chan, David Armbruster, Khosrow Adeli (2013). Marked Biological Variance in Endocrine and Biochemical Markers in Childhood: Establishment of Pediatric Reference Intervals Using Healthy Community Children from the CALIPER Cohort. *Clinical Chemistry*. DOI: https://doi.org/10.1373/clinchem.2013.204222