Fruit, vegetable and vitamin C intakes and plasma vitamin C: cross-sectional associations with insulin resistance and glycaemia in 9-10 year-old children.
OBJECTIVE
To examine whether low circulating vitamin C concentrations and low fruit and vegetable intakes were associated with insulin resistance and other Type 2 diabetes risk markers in childhood.


METHODS
We conducted a cross-sectional, school-based study in 2025 UK children aged 9-10 years, predominantly of white European, South-Asian and black African origin. A 24-h dietary recall was used to assess fruit, vegetable and vitamin C intakes. Height, weight and fat mass were measured and a fasting blood sample collected to measure plasma vitamin C concentrations and Type 2 diabetes risk markers.


RESULTS
In analyses adjusting for confounding variables (including socio-economic status), a one interquartile range higher plasma vitamin C concentration (30.9 μmol/l) was associated with a 9.6% (95% CI 6.5, 12.6%) lower homeostatic model assessment of insulin resistance value, 0.8% (95% CI 0.4, 1.2%) lower fasting glucose, 4.5% (95% CI 3.2, 5.9%) lower urate and 2.2% (95% CI 0.9, 3.4%) higher HDL cholesterol. HbA1c concentration was 0.6% (95% CI 0.2, 1.0%) higher. Dietary fruit, vegetable and total vitamin C intakes were not associated with any Type 2 diabetes risk markers. Lower plasma vitamin C concentrations in South-Asian and black African-Caribbean children could partly explain their higher insulin resistance.


CONCLUSIONS
Lower plasma vitamin C concentrations are associated with insulin resistance and could partly explain ethnic differences in insulin resistance. Experimental studies are needed to establish whether increasing plasma vitamin C can help prevent Type 2 diabetes at an early stage.
Population Health Research Institute, St George's, University of London, London, UK.
A S
AS
Donin
Population Health Research Institute, St George's, University of London, London, UK.
J E
JE
Dent
Population Health Research Institute, St George's, University of London, London, UK.
C M
CM
Nightingale
Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK.
N
N
Sattar
Population Health Research Institute, St George's, University of London, London, UK.
C G
CG
Owen
Population Health Research Institute, St George's, University of London, London, UK.
A R
AR
Rudnicka
Population Health Research Institute, St George's, University of London, London, UK.
M R
MR
Perkin
Medical Research Council Human Nutrition Research, Cambridge, UK.|Department of Nutritional Sciences, University of Surrey, Guildford, UK.
A M
AM
Stephen
Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
S A
SA
Jebb
Population Health Research Institute, St George's, University of London, London, UK.
D G
DG
Cook
Population Health Research Institute, St George's, University of London, London, UK.
P H
PH
Whincup
D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood*; D001786:Blood Glucose / Q000378:metabolism*; D002648:Child; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology; D004032:Diet; D004435:Eating / Q000502:physiology*; D005260:Female; D005638:Fruit; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D012307:Risk Factors; D012959:Socioeconomic Factors; D006113:United Kingdom / Q000453:epidemiology; D014675:Vegetables
D001786:Blood Glucose; D001205:Ascorbic Acid