Food rich in vitamin D include fish and fish liver oils...and small amounts are also found in beef liver, cheese, and egg yolks. These foods have the benefit of providing vitamin D3 (cholecalciferol) which is known to be more effective than the vitamin D2 found in some fortified foods.
The US National Institute of Health lists the nutrient values of foods high in vitamin D as follows:
Cod liver oil (1 tablespoon): 1,340 IUs
Sockeye salmon (3 oz. cooked): 794 IUs
Mackerel (3 oz. cooked): 388 IUs
Tuna fish (3 oz. canned in water & drained): 154 IUs
Milk (1 cup fortified): 115-124 IUs
Orange Juice (1 cup fortified): 100 IUs
Unless we are eating salmon every day, it is difficult to attain the daily 1,000 IUs of vitamin D recommended for adults by the Canadian Cancer Society; the 2,000 IUs recommended by Dr. Michael Holick (author of the UV Advantage); or the 5,000 IUs recommended by the Vitamin D Council, solely from foods rich in vitamin D.
IS COD LIVER OIL THE SOLUTION?
Cod liver oil certainly appears to be the most promising of the foods rich in vitamin D but there are several factors to consider before choosing this as your vitamin D program:
Vitamin D is not absorbed well without complementary vitamins
Cod liver oils vary significantly in the amount of vitamin D they provide
Several tablespoons a day may be necessary to maintain recommended blood levels of vitamin
Complementary Vitamins
The Vitamin D Council warns that a variety of vitamins and minerals are needed to help the body use vitamin D properly. These include:
magnesium
zinc
vitamin K2
boron
genestein
a tiny amount of vitamin A
Magnesium is the most important of these complementary factors but is rarely included with cod liver oil. Taking cod liver oil (or increasing vitamin D through supplements) could actually worsen an underlying magnesium deficiency...which is already common throughout North America.
Brands of Cod Liver Oil
Most brands of cod liver oil go through a process that removes all of the natural vitamins including vitamin D...although some manufacturers add vitamins to the final product. Cod liver oil that is unheated, fermented and produced with a filtering process that retains the natural vitamins is widely recommended. But most popular brands provide only 400 IUs of vitamin D per teaspoon (the equivalent of 1,200 IUs per tablespoon) which is well below recommended levels. During the winter months in northern regions (north of Boston, Rome and Beijing) several tablespoons would be required each day to maintain adequate blood levels-and additional magnesium would be required to facilitate absorption.
Many brands of cod liver oil have the benefit of providing EPA and DHA acids (which are valuable for the brain and nervous system) but few provide the higher dosage recommended by a growing number of vitamin D experts.
Although manufacturers argue that their oils provide more absorbable nutrients because of the high vitamin A content...this is widely disputed as vitamin A deficiency is rare in developed countries. Indeed, too much vitamin A may prove toxic and is particularly dangerous during pregnancy.
A good bone building supplement is an excellent complement to a diet of foods rich in vitamin D. A higher quality supplement will not only provide additional vitamin D3 but also the magnesium and vitamin K needed to facilitate absorption. Although cod liver oil is one of the foods rich in vitamin D...it may not provide as much absorbable vitamin D as expected while providing a false reassurance that intake is adequate.
http://ezinearticles.com/?Foods-Rich-in-Vitamin-D---Is-Cod-Liver-Oil-the-Solution?&id=4362161 - Food Rich in Vitamin D
