Related Experiment Video
Updated: Apr 5, 2026
A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
An Integrated Predictive Model of Population Serum 25-Hydroxyvitamin D for Application in Strategy Development for
Kevin D Cashman1, Andreas Kazantzidis2, Ann R Webb3
1Vitamin D Research Group, School of Food and Nutritional Science, and Department of Medicine, University College Cork, Cork, Ireland; k.cashman@ucc.ie.
Background:
To enable food-based strategies for the prevention of vitamin D deficiency to be evidence-based, there is a need to develop integrated predictive models of population serum 25-hydroxyvitamin D [25(OH)D] that are responsive to both solar and dietary inputs of vitamin D.
Objectives:
The objectives of this work were to develop and validate an integrated mathematical model with the use of data on UVB availability, exposure, and dietary intake to predict serum 25(OH)D concentrations in a nationally representative sample of adults, and then test the model's performance with the use of 3 hypothetical fortification scenarios as exemplars.
Methods:
Data on UVB availability and hours of sunlight in Ireland were used in a mathematical model to predict serum 25(OH)D in Irish adults aged 18-64 y. An equation from our dose-related vitamin D supplementation trial in adults was developed and integrated into the model, which allowed us to predict the impact of changes in dietary vitamin D on the contribution to annual serum 25(OH)D concentrations, accounting for seasonality of UVB availability. Recently published estimates of the impact of 3 vitamin D food fortification scenarios on vitamin D intake in a representative sample of Irish adults were used in the model as a test.
Results:
The UVB- and vitamin D intake-serum 25(OH)D components of the integrated model were both validated with the use of independent data. The model predicted that the percentage of vitamin D deficiency [serum 25(OH)D <30 nmol/L] in the adult population during an extended winter period was 18.1% (vs. 18.6% measured), which could be reduced in a stepwise manner with the incorporation of an increased number of vitamin D-fortified foods, down to 6.6% with the inclusion of enhanced fortified dairy-related products, fat spreads, fruit juice and drinks, and cereal products.
Conclusion:
Mathematical models have the ability to inform how vitamin D food fortification in various constructs may affect population serum 25(OH)D concentrations and the prevalence of vitamin D deficiency.
Related Concept Videos
01:23Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...
01:12Analysis of Population Pharmacokinetic Data
01:20Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and...
01:25Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
01:30Preventive Healthcare Services
00:59Model-Independent Approaches for Pharmacokinetic Data: Noncompartmental Analysis
One important characteristic of noncompartmental analyses is that drug exposure increases proportionally with increasing doses. This...