Now. If you need vitamin D (and I think most people do, but it’s wise to check with your doctor via a 25(OH)D, also called 25-hydroxyvitamin D test), the time to start taking it is now. I have taken Jarrow Formulas Vitamin D3 in the past and have been happy with it, but I prefer to get my vitamin D from cod liver oil because I think it’s got all of the co-factors for bioavailability and it has a lot of DHA and EPA. Plus, vitamin D should be taken with fat, and there’s a good amount (and the right kind) of fat in cod liver oil.
I personally like Carlson brand Norwegian Cod Liver Oil in lemon flavor, and it is on sale at Whole Foods through tomorrow (9/27/10). I just bought a 16.9 fl oz bottle today for $35.19, versus the regular price of $40.99. The Vitamin Shoppe has a web-only special right now for $23.07)
A 1 teaspoon serving has 400 IU of Vitamin D3, 500 mg of DHA, 400 mg of EPA and 40 mg of ALA. I try to take a tablespoon a day during cold and flu season and I feel it has a very significant cold and flu fighting effect if I get it started early enough in the season. Speaking of cold and flu season, see what is in my sick kit and more cold and flu items.