Reproducibility and relative validity of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones

Authors: ZWAKENBERG, SABINE - University Medical Center Utrecht; ENGELEN, ANOUK I - Wageningen University; DALMEIJER, GEERTJE - University Medical Center Utrecht; BOOTH, SARAH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; VERMEER, CEES - Maastricht University; DRIVJERS, JOSE M - National Institute For Public Health And The Environment (RIVM); OCKE, MARGA - Wageningen University; FESKENS, EDITH J - Wageningen University; VAN DER SCHOUW, YVONNE - University Medical Center Utrecht; BEULENS, JOLINE W - University Medical Center Utrecht

Submitted to: Nutrition Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2016
Publication Date: 8/16/2017
Citation: Zwakenberg, S.R., Engelen, A.P., Dalmeijer, G.W., Booth, S.L., Vermeer, C., Drivjers, J.M., Ocke, M.C., Feskens, E.M., Van Der Schouw, Y.T., Beulens, J.J. 2017. Reproducibility and relative validity of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones. Nutrition Journal. https://doi.org/10.1038/ejcn.2017.121.

Interpretive Summary: Several observational studies have investigated the relation of dietary vitamin K (phylloquinone and menaquinone) intake with occurrence of chronic diseases. Most of these studies relied on food frequency questionnaires to estimate the intake of two vitamin K forms (phylloquinone and menaquinones). However, none of these studies reported the reproducibility and relative validity of the food frequency questionnaire. Therefore, this study aims to investigate the relative validity and reproducibility of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones compared with 24-hour recalls and plasma markers of vitamin K status. In a cross sectional study among 63 men and 58 women, the food frequency questionnaire was completed 3 times over a 1-year period. Twelve monthly 24-hour recalls were collected as reference method. In addition, the relative validity of the food frequency questionnaire with two biomarkers of vitamin K status (plasma phylloquinone and desphospho uncarboxylated matrix Gla protein) was assessed cross sectionally among 507 postmenopausal women. Phylloquinone and long chain menaquinone intakes obtained from the food frequency questionnaire were correlated with corresponding intakes obtained from the 24-hour recalls. Plasma phylloquinone concentrations were correlated with phylloquinone intake, and plasma dp-ucMGP was negatively correlated with phylloquinone intake and long-chain menaquinone intake, but not with short chain menaquinones. The relative validity of our food frequency questionnaire to estimate intake of phylloquinone and short-chain menaquinones was low, but the relative validity for long-chain menaquinones was good. In contrast, the reproducibility of the food frequency questionnaire for both phylloquinone and menaquinone intake was good.

Technical Abstract: Background: Several observational studies have investigated the relation of dietary phylloquinone and menaquinone intake with occurrence of chronic diseases. Most of these studies relied on food frequency questionnaires (FFQ) to estimate the intake of phylloquinone and menaquinones. However, none of these studies reported the reproducibility and relative validity of the FFQ. Therefore, this study aims to investigate the relative validity and reproducibility of a food frequency questionnaire (FFQ) to estimate intake of dietary phylloquinone and menaquinones compared with 24-hour recalls and plasma markers of vitamin K status. Methods: In a cross sectional study among 63 men and 58 women, the FFQ was completed 3 times over a 1-year period. Twelve monthly 24- hour recalls were collected as reference method. In addition, the relative validity of the FFQ with plasma phylloquinone and desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) as reference, was assessed cross-sectionally among 507 postmenopausal women. Results: The relative validity for phylloquinone intake compared with 24-hour recalls was generally lower for women (p=0.28) than men (p=0.40). The relative validity for intake of short-chain menaquinones was 0.30, for both men and women. Long-chain menaquinones were correlated with the 24-hour recalls with correlations of 0.69 (0.53;0.80) and 0.60 (0.40;0.74), for men and women respectively. The FFQ was reproducible for phylloquinone and menaquinone intake, with Spearman correlations ranging from 0.59 (0.39;0.73) to 0.80 (0.68;0.87) for men and women. Plasma phylloquinone concentrations were correlated with phylloquinone intake, with a correlation coefficient of 0.17 (0.08;0.25). Plasma dp-ucMGP was negatively correlated with phylloquinone intake (p= 0.10 (-0.18;-0.01)) and long chain menaquinone intake (-0.15 (-0.24;-0.07)), but not with short chain menaquinones (p=-0.02 (-0.11; 0.06)). Conclusions: The relative validity of our FFQ to estimate intake of phylloquinone and short-chain menaquinones was low, but the relative validity for long-chain menaquinones was good. The reproducibility of the FFQ for both phylloquinone and menaquinone intake was good.