Ulrike Lehmann3,5, Hanne Rosendahl Gjessing4, Frank Hirche3, Andreas Mueller-Belecke7, Oddrun Anita Gudbrandsen5, Per Magne Ueland8, Gunnar Mellgren4, Lotte Lauritzen9, Helen Lindqvist10, Anita Lill Hansen6, Arja T Erkkilä11, Gerda K Pot12, Gabriele I Stangl3, and Jutta Dierkes5,*
3Institute of Agricultural and Nutritional Sciences, Martin Luther University of Halle-Wittenberg, Halle, Germany;
4Departments of Clinical Science,
5Clinical Medicine, and
6Psychosocial Science, University of Bergen, Bergen, Norway;
7Institute of Inland Fisheries, Potsdam-Sacrow, Germany;
8Bevital AS, Bergen, Norway;
9Department of Nutrition, Exercise, and Sports, Faculty of Sciences, University of Copenhagen, Copenhagen, Denmark;
10Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
11Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland; and
12Diabetes and Nutritional Sciences Division, King’s College London, London, United Kingdom
↵1 Supported by grant 01EA1323A from the German Federal Ministry of Education and Research and by personal grants from The Research Council of Norway (to UL; grant 227506/F11) and from Bergen Medical Research Foundation (to OAG).
↵2 Supplemental Text and Supplemental Tables 1–3 are available from the “Supplemental data” link in the online posting of the article and from the same link in the online table of contents at http://ajcn.nutrition.org.
↵*To whom correspondence should be addressed. E-mail: jutta.dierkes at med.uib.no.
Background: It is well known that fish is the major natural source of vitamin D in the diet; therefore, this meta-analysis investigated the influence of fish consumption in randomized controlled trials (RCTs) on serum 25-hydroxyvitamin D [25(OH)D] concentrations.
Objective: A literature search was carried out in Medline, Embase, Web of Science, and the Cochrane Library (up to February 2014) for RCTs that investigated the effect of fish consumption on 25(OH)D concentrations in comparison to other dietary interventions.
Results: Seven articles and 2 unpublished study data sets with 640 subjects and 14 study groups met the inclusion criteria and were included in this meta-analysis. Compared with controls, the consumption of fish increased 25(OH)D concentrations, on average, by 4.4 nmol/L (95% CI: 1.7, 7.1 nmol/L; P < 0.0001, I2 = 25%; 9 studies). The type of the fish also played a key role: the consumption of
- fatty fish resulted in a mean difference of 6.8 nmol/L (95% CI: 3.7, 9.9 nmol/L; P < 0.0001, I2 = 0%; 7 study groups), whereas for
- lean fish the mean difference was 1.9 nmol/L (95% CI: −2.3, 6.0 nmol/L; P < 0.38, I2 = 37%; 7 study groups).
Short-term studies (4–8 wk) showed a mean difference of 3.8 nmol/L (95% CI: 0.6, 6.9 nmol/L; P < 0.02, I2 = 38%; 10 study groups),
whereas in long-term studies (∼6 mo) the mean difference was 8.3 nmol/L (95% CI: 2.1, 14.5 nmol/L; P < 0.009, I2 = 0%; 4 study groups).
Conclusion: As the major food source of vitamin D, fish consumption increases concentrations of 25(OH)D, although recommended fish intakes cannot optimize vitamin D status.
- Cooking reduces vitamin D content by about 30 percent – Oct 2013
- 11,000 IU vitamin D daily from traditional Norwegian diet of cod, cod liver, cod-liver oil, and roe – 2004
Can raise vitamin D levels a LOT if eat a LOT of fatty fish
- Cost of getting 400 IU of vitamin D from food has risen much faster than CPI – April 2015
Increasing vitamin D levels by supplementation is far less expense than eating fish
- Farmed fish not have enough vitamin D to increase levels – RCT Feb 2014