Vitamin D: van Groningen model estimate
25(OH)D in two units and a weight-based research estimate. No automatic treatment schedule.
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Calculation
Result
- Current 25(OH)D
- 42.0 nmol/L
- Total van Groningen model estimate
- 99000 IU
Research estimate, not a single dose or a dosing schedule.
Research estimate, not a single dose or a dosing schedule. Reference ranges are population benchmarks from the cited sources. Laboratories use their own ranges, and interpretation depends on clinical context: discuss the result with your physician.
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How it is calculated
The van Groningen (2010) model relates total cholecalciferol dose to weight and baseline 25(OH)D. This tool uses the research target of 75 nmol/L, baseline below 50 nmol/L and weight 35–125 kg. The lower weight limit restricts the interface to an adult context; age and clinical exclusions require clinician assessment. It does not select a schedule, maintenance dose or follow-up interval. Endocrine Society 2024 does not establish a universal target 25(OH)D for disease prevention in healthy people.
Formula
Total model estimate (IU) = 40 × (75 − 25(OH)D, nmol/L) × weight (kg). 1 ng/mL = 2.496 nmol/L.
Limits of the method
A research calculation for discussion with a clinician, not an individual prescription. Do not use it for self-treatment during pregnancy, in children, or with calcium disorders, kidney disease, malabsorption or granulomatous disease. The model does not account for medicines or supplements; the total must not be taken as a single dose.
Sources of the method
This calculation is for reference only and is not medical advice, a diagnosis or a prescription. If you have a medical condition, are pregnant, take medication or have any doubts, discuss the result with a physician or a qualified nutrition professional.
How to use the calculation
Enter the starting values
The van Groningen (2010) model relates total cholecalciferol dose to weight and baseline 25(OH)D. This tool uses the research target of 75 nmol/L, baseline below 50 nmol/L and weight 35–125 kg. The lower weight limit restricts the interface to an adult context; age and clinical exclusions require clinician assessment. It does not select a schedule, maintenance dose or follow-up interval. Endocrine Society 2024 does not establish a universal target 25(OH)D for disease prevention in healthy people.
Adjust the parameters
Total model estimate (IU) = 40 × (75 − 25(OH)D, nmol/L) × weight (kg). 1 ng/mL = 2.496 nmol/L.
Read the result
A research calculation for discussion with a clinician, not an individual prescription. Do not use it for self-treatment during pregnancy, in children, or with calcium disorders, kidney disease, malabsorption or granulomatous disease. The model does not account for medicines or supplements; the total must not be taken as a single dose.
Frequently asked questions
What does the calculation show?
The van Groningen (2010) model relates total cholecalciferol dose to weight and baseline 25(OH)D. This tool uses the research target of 75 nmol/L, baseline below 50 nmol/L and weight 35–125 kg. The lower weight limit restricts the interface to an adult context; age and clinical exclusions require clinician assessment. It does not select a schedule, maintenance dose or follow-up interval. Endocrine Society 2024 does not establish a universal target 25(OH)D for disease prevention in healthy people.
What limitations apply?
A research calculation for discussion with a clinician, not an individual prescription. Do not use it for self-treatment during pregnancy, in children, or with calcium disorders, kidney disease, malabsorption or granulomatous disease. The model does not account for medicines or supplements; the total must not be taken as a single dose.
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What next
Formula breakdowns, biomarker reference ranges and nutrition articles with cited sources are in the NutriFit knowledge base.
Go to the knowledge base