Turkiye Klinikleri Journal of Health Sciences

.: ORIGINAL RESEARCH
Development and Validity of a Food Frequency Questionnaire for Assessing Vitamin C Intake in Turkish Adults
Yetişkin Türklerde C Vitamini Alımının Değerlendirilmesine Yönelik Besin Tüketim Sıklığı Anketinin Geliştirilmesi ve Geçerliliği
Elif EMİROĞLUa,b, Fatma Esra GÜNEŞa, Berna KARAKOYUNc
aDepartment of Nutrition and Dietetics, Marmara University Faculty of Health Sciences, İstanbul, TURKEY
bDepartment of Nutrition and Dietetics, İstinye University Faculty of Health Sciences, İstanbul, TURKEY
cDepartment of Physiology, University of Health Sciences Hamidiye Faculty of Medicine, İstanbul, TURKEY
Turkiye Klinikleri J Health Sci. 2020;5(3):408-12
doi: 10.5336/healthsci.2019-73059
Article Language: EN
Full Text
ABSTRACT
 Objective: This study aimed to evaluate the validity of a food frequency questionnaire (FFQ) developed to determine vitamin C intake. Material and Methods: This research was carried out at Istanbul University Faculty of Dentistry between October 2017 and May 2018. There were 75 individuals in this study, who were 18-65 years old. In order to determine the level of vitamin C intake of individuals, a FFQ was formed which contains the consumption frequency and the amount of consumption of 83 foods and its language is Turkish. After the determination of the plasma ascorbic acid level (PAAL) of the individuals, the validity of the questionnaire was examined by Spearman correlation test, Bland Altman plot and kappa statistics. All statistical analysis were performed using the IBM SPSS Statistics 20 Software and statistically significant differences were determined using a p value <0.05. Results: A total of 75 people (31 male and 44 female) participated in this study, and the mean age was 35.69±10.35 years. The median PAAL was 7.94 mg/L, while the median intake of vitamin C was 136.84 mg/d. There was a positive correlation between PAAL and intake of vitamin C (r=0.41; p<0.001). The values of PAAL and intake of vitamin C calculated by FFQ were divided into quartiles, and the rate of the classifying into the same or adjacent quartile was 81.4%. Conclusion: In conclusion, this questionnaire can be used to determine intake of vitamin C in Turkish adults.

Keywords: Ascorbic acid; validation studies; nutritional status
ÖZET
 Amaç: Bu çalışma, C vitamini alımını belirlemek amacıyla geliştirilen bir besin tüketim sıklığı anketinin (food frequency questionnaire: FFQ) geçerliliğini değerlendirmeyi amaçlamaktadır. Gereç ve Yöntemler: Bu çalışma, Ekim 2017 - Mayıs 2018 tarihleri arasında İstanbul Üniversitesi Diş Hekimliği Fakültesi'nde gerçekleştirilmiştir. Çalışmaya 18-65 yaş arasındaki 75 gönüllü birey katılmıştır. Bireylerin C vitamini alımlarını belirlemek için, toplam 83 besinin tüketim miktarı ve sıklığını içeren Türkçe bir besin tüketim sıklığı anketi oluşturulmuştur. Bireylerin plazma askorbik asit seviyelerinin belirlenmesinin ardından anketin geçerliliği Spearman korelasyon testi, Bland Altman grafiği ve kappa istatistiği ile incelenmiştir. Tüm istatistiksel analizler IBM SPSS Statistics 20 yazılımı kullanılarak yapılmış ve p<0,05 değeri statistiksel olarak anlamlı kabul edilmiştir. Bulgular: Çalışmaya katılan 75 kişiden 31'i (%41,3) erkek, 44'ü (%58,7) kadındır. Medyan plazma askorbik asit seviyesi 7,94 mg/L iken, medyan C vitamini alımı 136,84 mg/gün'dür. Plazma askorbik asit seviyesi ile C vitamini alımı arasında pozitif bir korelasyon bulunmuştur (r=0,41; p<0,001). Plazma askorbik asit düzeyleri ve FFQ ile hesaplanan C vitamini alım miktarları çeyreklere ayrılmış; aynı veya bitişik çeyrekte sınıflandırma oranı %81.4 olarak bulunmuştur. Sonuç: Sonuç olarak, bu anket yetişkin Türklerde C vitamini alım düzeyini belirlemek için kullanılabilir.

Anahtar Kelimeler: Askorbik asid; doğrulama çalışmaları; beslenme durumu
REFERENCES:
  1. Naska A, Lagiou A, Lagiou P. Dietary assessment methods in epidemiological research: current state of the art and future prospects. F1000Res. 2017;6:926.[Crossref] [PubMed] [PMC] 
  2. Dwyer JT and Bailey RL. Nutrition 101: The Concept of Nutritional Status, Standards, and Guides for Nutrient Intakes, Eating Patterns, and Nutrition. In: Rippe JM, ed. Nutrition in Lifestyle Medicine. 1st ed. Switzerland: Springer International Publishing; 2017. p.17-9.[Crossref] [PubMed] [PMC] 
  3. Thompson FE, Subar AF. Dietary Assessment Methodology. In: Coulston AM, Boushey CJ, Ferruzzi M, Delahanty L, eds. Nutrition in the Prevention and Treatment of Disease. 4th ed. Longon: Elsevier; 2017. p.5.
  4. Width M, Reinhard T. [Nutritional Assessment]. Klinik Beslenme İçin Temel Cep Kitabı. 2nd ed. İstanbul: Nobel Tıp Kitabevi; 2019. p.35-40.
  5. Hammond KA, Mahan LK. Intake: Analysis of the Diet. In: Mahan LK, Raymond JL. Krause's Food & the Nutrition Care Process. 14th ed. St. Louis: Elsevier; 2017. p.52-61.
  6. Lai JS, Attia J, McEvoy M, Hure AJ. Biochemical validation of the older Australian's food frequency questionnaire using carotenoids and vitamin E. Nutrients. 2014;6(11):4906-17.[Crossref] [PubMed] [PMC] 
  7. Padayatty SJ, Katz A, Wang Y, Eck P, Kwon O, Lee JH, et al. Vitamin C as an antioxidant: evaluation of its role in disease prevention. J Am Coll Nutr. 2003;22(1):18-35.[Crossref] [PubMed] 
  8. Gürdöl F. [Vitamins]. Beslenme Biyokimyası. 2nd ed. İstanbul: Nobel Tıp Kitabevi; 2018. p.113-4.
  9. Merdol TK. [The amount of nutrients to be consumed Daily and nutrition guides.]. Temel Beslenme ve Diyetetik. 1st ed. Ankara: Ayrıntı Yayınları; 2015. p.100.
  10. Yılmaz İ. [Some food containing antioxidants and oxidatif stress]. İnönü Üniversitesi Tıp Fakültesi Dergisi. 2010;17(2):143-53.[Link] 
  11. Combs GF, McClung JP. Vitamin C. The Vitamins - Fundamental Aspects in Nutrition and Health. 5th ed. London: Elsevier; 2017. p.271.
  12. Dehghan M, Akhtar-Danesh N, McMillan CR, Thabane L. Is plasma vitamin C an appropriate biomarker of vitamin C intake? A systematic review and meta-analysis. Nutr J. 2007;6:41.[Crossref] [PubMed] [PMC] 
  13. Johansson G. The validation of dietary assessment. Nutritional Epidemiology. 1st ed. Sweden: Halmstad University Press; 2014. p.30.
  14. Erbil K. Laboratuvar Testleri ve Klinik Kullanımı. 1st ed. Ankara: GATA Komutanlığı Basımevi; 2007. p.595.
  15. Maxfield L, Crane JS. Vitamin C Deficiency. 2020. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2020.[PubMed] 
  16. Baysal A. [Vitamins]. Beslenme. 13th ed. Ankara: Hatiboğlu Basım ve Yayım San Tic Ltd Şti; 2011. p.243.
  17. Güneş E, Nimeryüz N. Besin Atlası. 1st ed. İstanbul: Ada Ofset; 2008.
  18. Rakıcıoğlu N, Tek NA, Ayaz A, Pekcan G. Yemek ve Besin Fotoğraf Kataloğu. 1st ed. Ankara: Ata Ofset Matbaacılık; 2009.
  19. Hayran O, Özbek H. [Significance tests for the analysis of data obtained from two groups]. Sağlık Bilimlerinde Araştırma ve İstatistik Yöntemler. 2nd ed. İstanbul: Nobel Tıp Kitabevleri; 2017. p.157.
  20. Hayran O, Özbek H. [Correlation analysis]. Sağlık Bilimlerinde Araştırma ve İstatistik Yöntemler. 2nd ed. İstanbul: Nobel Tıp Kitabevleri; 2017. p.264.
  21. Aksoy M. [Vitamins]. Beslenme Biyokimyası. 5th ed. Ankara: Hatiboğlu Yayınları; 2016. p.486-7.
  22. Cahill LE, El-Sohemy A. Vitamin C transporter gene polymorphisms, dietary vitamin C and serum ascorbic acid. J Nutrigenet Nutrigenomics. 2009;2(6):292-301.[Crossref] [PubMed] 
  23. Güneş FE, Elmacıoğlu F, Aktaç Ş, Sağlam D. Development and Validation of a Semi-Quantitative Food Frequency Questionnaire to Assess Dietary Intake of Turkish School-Aged Children. Pol J Food Nutr Sci. 2016;66(2):129-37.[Crossref] 
  24. Yang M, Wang Y, Davis CG, Lee SG, Fernandez ML, Koo SI, et al. Validation of an FFQ to assess antioxidant intake in overweight postmenopausal women. Public Health Nutr. 2014;17(7):1467-75.[Crossref] [PubMed] 
  25. Zalaket J, Matta J, Hanna-Wakim L. Development, validity, and reproducibility of a semiquantitative food frequency questionnaire for the assessment of antioxidant vitamins intake in Lebanon. Nutrition. 2019;58:11-17.[Crossref] [PubMed] 
  26. Santosh HN, David C. A Food Frequency Questionnaire to Determine the Intake of Vitamin C: A Pilot Validation Study. Rom J Diabetes Nutr Metab Dis. 2017;24(2):95-9.[Crossref] 
  27. Porrini M, Gentile MG, Fidanza F. Biochemical validation of a self-administered semi-quantitative food-frequency questionnaire. Br J Nutr. 1995;74(3):323-33.[Crossref] [PubMed] 

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