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Tea and coffee consumption in relation to vitamin D and calcium levels in Saudi adolescents

Abdulaziz Al-Othman12, Sara Al-Musharaf3, Nasser M Al-Daghri11145*, Sobhy Yakout4, Khalid M Alkharfy16, Yousef Al-Saleh17, Omar S Al-Attas145, Majed S Alokail145, Osama Moharram8, Shaun Sabico4, Sudhesh Kumar9 and George P Chrousos104

Author Affiliations

1 Prince Mutaib Chair for Biomarkers of Osteoporosis, King Saud University, Riyadh, KSA

2 College of Applied Medical Sciences, King Saud University, Riyadh, KSA

3 College of Science, King Saud University Women's Section, Riyadh, KSA

4 Biomarkers Research Program, Biochemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia (KSA

5 Center of Excellence in Biotechnology Research, King Saud University, Riyadh, KSA

6 Clinical Pharmacy Department, College of Pharmacy, King Saud University, Riyadh, KSA

7 College of Medicine, King Saud University of Health Sciences, Riyadh, KSA

8 King Abdulaziz University Hospital, King Saud University, Riyadh, KSA

9 Clinical Sciences Research Institute, Diabetes and Metabolism Unit, Warwick University, Coventry, CV47AL, UK

10 First Department of Pediatrics, Athens University Medical School, Athens, 11527, Greece

11 Prince Mutaib Bin Abdullah Chair for Osteoporosis, Biochemistry Department, College of Science, King Saud University, PO Box, 2455, Riyadh, 11451, Kingdom of Saudi Arabia

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Nutrition Journal 2012, 11:56  doi:10.1186/1475-2891-11-56

Published: 20 August 2012

Abstract

Background

Coffee and tea consumption was hypothesized to interact with variants of vitamin D-receptor polymorphisms, but limited evidence exists. Here we determine for the first time whether increased coffee and tea consumption affects circulating levels of 25-hydroxyvitamin D in a cohort of Saudi adolescents.

Methods

A total of 330 randomly selected Saudi adolescents were included. Anthropometrics were recorded and fasting blood samples were analyzed for routine analysis of fasting glucose, lipid levels, calcium, albumin and phosphorous. Frequency of coffee and tea intake was noted. 25-hydroxyvitamin D levels were measured using enzyme-linked immunosorbent assays.

Results

Improved lipid profiles were observed in both boys and girls, as demonstrated by increased levels of HDL-cholesterol, even after controlling for age and BMI, among those consuming 9–12 cups of coffee/week. Vitamin D levels were significantly highest among those consuming 9–12 cups of tea/week in all subjects (p-value 0.009) independent of age, gender, BMI, physical activity and sun exposure.

Conclusion

This study suggests a link between tea consumption and vitamin D levels in a cohort of Saudi adolescents, independent of age, BMI, gender, physical activity and sun exposure. These findings should be confirmed prospectively.

Keywords:
Coffee intake; Tea intake; Vitamin D levels; Saudi adolescents