Vitamin D status and PUFA ratios in a national representative cross-section of healthy, middle-aged Norwegian women—the Norwegian Women and Cancer Post-Genome Cohort

Scand J Public Health. 2014 Dec;42(8):814-20. doi: 10.1177/1403494814550519. Epub 2014 Sep 26.


Aims: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Fatty acids; PUFA; epidemiology; fatty fish; nutrition; vitamin D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cohort Studies
  • Cross-Sectional Studies
  • Diet / statistics & numerical data
  • Fatty Acids, Unsaturated / administration & dosage
  • Fatty Acids, Unsaturated / analysis
  • Fatty Acids, Unsaturated / blood*
  • Female
  • Fishes
  • Humans
  • Middle Aged
  • Norway
  • Vitamin D / administration & dosage
  • Vitamin D / blood*


  • Fatty Acids, Unsaturated
  • Vitamin D