Diet, Environmental Factors, and Lifestyle Underlie the High Prevalence of Vitamin D Deficiency in Healthy Adults in Scotland and Supplementation Reduces the Proportion That Are Severely Deficient1,2,3

1. Lina Zgaga⁴,⁵,¹⁰,^*, 
2. Evropi Theodoratou⁴,⁵,¹⁰, 
3. Susan M. Farrington⁵,
4. Felix Agakov⁴, 
5. Albert Tenesa⁵, 
6. Marion Walker⁵, 
7. Susan Knox⁶,
8. A. Michael Wallace⁶,¹¹, 
9. Roseanne Cetnarskyj⁷, 
10. Geraldine McNeill⁸,
11. Janet Kyle⁸, 
12. Mary E. Porteous⁹, 
13. Malcolm G. Dunlop⁵, and
14. Harry Campbell⁴,⁵,^*

+Author Affiliations

1. ⁴Centre for Population Health Sciences, University of Edinburgh, Edinburgh EH8 9AG, UK
2. ⁵Colon Cancer Genetics Group and Academic Coloproctology, Institute of Genetics and Molecular Medicine, University of Edinburgh and MRC Human Genetics Unit, Western General Hospital, Edinburgh, EH4 2XU, UK
3. ⁶Department of Clinical Biochemistry, Royal Infirmary, Glasgow G4 0SF, UK
4. ⁷School of Nursing, Midwifery and Social Care, Faculty of Health, Life and Social Sciences, Edinburgh Napier University, Edinburgh, UK
5. ⁸Public Health Nutrition Research Group, The Rowett Institute of Nutrition and Health, Bucksburn, Aberdeen AB21 9SB, UK
6. ⁹Southeast of Scotland Clinical Genetic Services, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK

1. *To whom correspondence should be addressed. E-mail: lina.zgaga@ed.ac.uk orharry.campbell@ed.ac.uk.

Abstract

Vitamin D deficiency has recently been implicated as a possible risk factor in the etiology of numerous diseases, including nonskeletal conditions. In humans, skin synthesis following exposure to UVB is a potent source of vitamin D, but in regions with low UVB, individuals are at risk of vitamin D deficiency. Our objectives were to describe the prevalence of vitamin D deficiency and to investigate determinants of plasma 25-hydroxyvitamin D (25-OHD) concentrations in a high northern latitude country. Detailed dietary, lifestyle, and demographic data were collected for 2235 healthy adults (21–82 y) from Scotland. Plasma 25-OHD was measured by liquid chromatography-tandem MS. Among study participants, 34.5% were severely deficient (25-OHD<25 nmol/L) and 28.9% were at high risk of deficiency (25–40 nmol/L). Only 36.6% of participants were at low risk of vitamin D deficiency or had adequate levels (> 40 nmol/L). Among participants who were taking supplements, 21.3% had a May-standardized 25-OHD concentration > 50 nmol/L, 54.2% had 25–50 nmol/L, and 24.5% had <25 nmol/L, whereas this was 15.6, 43.3, and 41%, respectively, among those who did not take supplements (P < 0.0001). The most important sources of vitamin D were supplements and fish consumption. Vitamin D deficiency in Scotland is highly prevalent due to a combination of insufficient exposure to UVB and insufficient dietary intake. Higher dietary vitamin D intake modestly improved the plasma 25-OHD concentration (P = 0.02) and reduced the proportion of severely deficient individuals (P < 0.0001). In regions with low UVB exposure, dietary and supplement intake may be much more important than previously thought and consideration should be given to increasing the current recommended dietary allowance of 0–10 μg/d for adults in Scotland.

• Manuscript received: February 16, 2011.
• Initial review completed: March 16, 2011.
• Revision accepted: May 24, 2011.

Diet, Faktor Lingkungan, dan Gaya Hidup Mendasari Prevalensi Tinggi Vitamin D Kekurangan Dewasa Sehat di Skotlandia dan Suplementasi Mengurangi Proporsi Yang Parah Deficient1, 2,3