Most Americans are deficient in vitamin D—or close to it—and need to get much more from pills or foods. As it happens, fatty fish are the richest food sources by far, with tuna, sardines, mackerel, and salmon leading the pack.
But not all salmon are good sources of vitamin D… with farmed salmon lagging far behind their wild cousins.
Three years ago, we reported that Boston University tests found much more vitamin D in wild salmon than in farmed salmon (Lu Z 2007).
Critically, the BU researchers found that a sample of wild Pacific salmon had four times more vitamin D (988 IU), compared with the farmed Atlantic salmon (245 IU).
The amount found in wild salmon was almost five times the US RDA (200 IU) from birth through age 51... which most researchers want raised to at least 1000 IUs per day.
For more on that study, see “Wild Salmon Affirmed as Top Vitamin D Source.”
Now, the results of tests commissioned by Canada’s CTV News affirm those findings... and then some.
Canadian TV station finds wild salmon far higher in vitamin D
When CTV sent samples of both to be tested, the results showed that wild Pacific salmon had eight times more vitamin D than farmed Atlantic salmon.
(Most farmed salmon is of the Atlantic species, which was nearly exterminated by damming of rivers in America, and by lice and other pressures from poorly sited and designed Norwegian and Scottish ocean-pen salmon farms.)
Specifically, the samples of wild Pacific salmon had more than 500 IU of vitamin D per 3.5 oz serving, while farmed salmon had only 60 IU. And, the farmed salmon had three times as much fat as the wild salmon (13 percent fat, versus only 2.5 percent).
Because fat has more than twice as many calories as protein or carbohydrates, this means that farmed salmon also has more calories than wild salmon.
Their higher fat content explains why most tests find that most farmed salmon have slightly more omega 3 fatty acids than most (not all) wild salmon… though the difference is minor.
Unfortunately, the CTV report failed to mention that, compared with wild salmon, farmed salmon is much higher in omega-6 fats, which compete with omega-3s in our bodies for absorption into cell membranes, and tend to promote inflammation.
That excess of omega-6 fatty acids can have undesirable consequences, as Norwegian scientists found when they fed farmed salmon to volunteers… see “Farmed Salmon's Diet Yields Unhealthful Cardiovascular Effects.”
- CTV News. Farmed vs. wild salmon – which is better? March 5, 2010. Accessed at http://www.ctvbc.ctv.ca/servlet/an/local/CTVNews/20100219/ bc_ctv_investigates_food_fish_100219/201
- Holick MF. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin Proc. 2006 Mar;81(3):353-73. Review.
- Hollis BW. Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D. J Nutr. 2005 Feb;135(2):317-22. Review. Whiting SJ, Green TJ, Calvo MS. Vitamin D intakes in North America and Asia-Pacific countries are not sufficient to prevent vitamin D insufficiency. J Steroid Biochem Mol Biol. 2007 Jan 9; [Epub ahead of print]
- Vieth R, Cole DE, Hawker GA, Trang HM, Rubin LA. Wintertime vitamin D insufficiency is common in young Canadian women, and their vitamin D intake does not prevent it. Eur J Clin Nutr. 2001 Dec;55(12):1091-7.
- Lu Z, Chen TC, Zhang A, Persons KS, Kohn N, Berkowitz R, Martinello S, Holick MF. An evaluation of the vitamin D(3) content in fish: Is the vitamin D content adequate to satisfy the dietary requirement for vitamin D? J Steroid Biochem Mol Biol. 2007 Jan 29; [Epub ahead of print] doi:10.1016/j.jsbmb.2006.12.010