Olsen Karina Standahl, Aksnes Lage, Frøyland Livar, Lund Eiliv, Rylander Charlotta
Department of Community Medicine, UiT The Arctic University of Norway, Tromsø, Norway
Departments of Clinical Science Section for Paediatrics, Haukeland University Hospital, Bergen, Norway.
Scand J Public Health. 2014 Dec;42(8):814-20. doi: 10.1177/1403494814550519. Epub 2014 Sep 26.
Vitamin D and polyunsaturated fatty acids (PUFAs) are derived from partially overlapping sources. Vitamin D is produced in the skin after sun exposure, but is also derived from fatty fish and fish oils. Dietary PUFAs are mainly derived from plant oils that are rich in n-6 PUFAs, but fatty fish provides high amounts of the marine n-3 PUFAs. The Western diet provides an excess of n-6 PUFAs compared to n-3 PUFAs, and the ratios of these may influence human health. Here, we investigated the potential associations of plasma concentrations of vitamin D, marine PUFAs and PUFA ratios.
Plasma concentrations of vitamin D (25(OH)D), marine PUFAs, and PUFA ratios were measured in 372 women from the Norwegian Women and Cancer (NOWAC) Post-Genome Cohort. Covariability was examined in 310 non-users of cod liver oil, using Spearman's rank correlation and linear regression.
In non-users of cod liver oil, the average concentration of vitamin D was 40.3 nmol/L, and marine PUFA concentration was 0.2 mg/g. PUFA ratios were dominated by the n-6 fatty acids. Vitamin D levels were significantly associated with marine fatty acids and weakly associated with PUFA ratios.
Concentrations of vitamin D and marine PUFAs were below recommended levels. The correlation analyses indicated that health-related effects of vitamin D and marine PUFAs respectively may be hard to separate in epidemiological studies. However, measured health effects of PUFA ratios and vitamin D are likely to derive from the influence of the two factors separately. The presented results are the first to show these associations in a nationally representative cohort.
维生素D和多不饱和脂肪酸（PUFAs）的来源部分重叠。维生素D在皮肤经阳光照射后产生，但也来源于富含脂肪的鱼类和鱼油。膳食中的多不饱和脂肪酸主要来源于富含n-6多不饱和脂肪酸的植物油，但富含脂肪的鱼类提供大量的海洋n-3多不饱和脂肪酸。与n-3多不饱和脂肪酸相比，西方饮食中n-6多不饱和脂肪酸过量，它们的比例可能会影响人类健康。在此，我们研究了维生素D、海洋多不饱和脂肪酸的血浆浓度与多不饱和脂肪酸比例之间的潜在关联。
在挪威女性与癌症（NOWAC）后基因组队列的372名女性中测量了维生素D（25(OH)D）、海洋多不饱和脂肪酸的血浆浓度以及多不饱和脂肪酸比例。使用Spearman等级相关性和线性回归对310名未服用鱼肝油的参与者进行了协变量分析。
在未服用鱼肝油的参与者中，维生素D的平均浓度为40.3 nmol/L，海洋多不饱和脂肪酸浓度为0.2 mg/g。多不饱和脂肪酸比例以n-6脂肪酸为主。维生素D水平与海洋脂肪酸显著相关，与多不饱和脂肪酸比例弱相关。
维生素D和海洋多不饱和脂肪酸的浓度低于推荐水平。相关性分析表明，在流行病学研究中，维生素D和海洋多不饱和脂肪酸各自对健康的影响可能难以区分。然而，多不饱和脂肪酸比例和维生素D对健康的实测影响可能分别源于这两种因素的作用。本研究结果首次在具有全国代表性的队列中显示了这些关联。
