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
Sammanfattning
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.