Foods High in Vitamin D

Vitamin D is a fat soluble molecule very important to the body to function properly. Adequate amounts promote efficient calcium absorption in the gut and maintain an adequate concentration of calcium and phosphate in the blood so as to enable normal mineralization of bones. Vitamin D deficiencies may cause brittle bones. Also, this vitamin is involved in the modulation of neuromuscular and immune function.

Vitamin D by itself is inert. It must undergo chemical modifications (most precisely hydroxylations) to become active within the body. One of these activations occur in the liver where it is converted to 25-hydroxyvitamin D (known as calcidiol). The other activation occurs in the kidney where it is converted to the physiologically active 1,25-dihydroxyvitamin D (known as calcitriol).

How Much Vitamin Do We Need to Take In?

The Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies has developed intake reference values for many nutrients including vitamin D. The adequate intake for this nutrient will depend of the person's age. For example, for people up to 50 years old, 5 micrograms (mcg) per day is recommended. From 51 to 70, 10 mcg, and for people older than 71, 15 mcg. Since adequate intakes for vitamin D were established in 1997 and new data has been obtained since then, the FNB established (in 2008) an expert committee to revise the recommended values for vitamin D intake. The committee is expected to issue a new report in May 2010.

What Foods Contain Vitamin D?

Unfortunately, very few foods are a natural resource of vitamin D. The best sources of vitamin D in food are of marine origin, including salmon, tuna, and mackerel (fish liver oils are among the best). Other sources include mushrooms, beef liver, cheese, and egg yolk.

Fortified foods constitute the source of vitamin D in many countries. In the United States for example, almost all milk is fortified with 100 IU (2.5 mcg)/cup of vitamin D. Ready-to-eat breakfast cereals are usually fortified with vitamin D, as well as orange juice, yogurt, and margarine.

The U.S. Department of Agriculture's Nutrient Database website lists many foods and nutrient composition of these foods. From this database, here is a compilation of the foods with the highest content of vitamin D:

Natural foods high in vitamin D

-Cod liver oil (1 tablespoon) 1,360 International Units (IU) -- 40 IU is equal to 1 microgram

-Salmon (cooked - 3 ounces) 794 IU

-Mackerel (cooked - 3 ounces) 388 IU

-Tuna fish (canned in water - drained - 3 ounces) 154 IU

--Egg (1 whole) 25 IU

-Cheese (swiss - 1 ounce) 6 IU

-Fortified foods with high content of vitamin D

-Instant baby formula 310-320 IU

-Orange juice (fortified with vitamin D - 1 cup - check product labels, as amount of added vitamin D varies) 100 IU

-Yogurt (fortified with 20% of the DV for vitamin D - 6 ounces) 80 IU

-Margarine, fortified - 1 tablespoon) 60 IU

-Ready-to-eat cereal (fortified with 10% of the DV for vitamin D - 0.75-1 cup) 40 IU

DV---Daily Value

Sources:

Institute of Medicine, Food and Nutrition Board. 1997. Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. National Academy Press. Washington D.C.

Dietary Reference Intakes for Vitamin D and Calcium: http://www.iom.edu/Activities/Nutrition/DRIVitDCalcium.aspx

The U.S. Department of Agriculture's Nutrient Database Website, http://www.nal.usda.gov/fnic/foodcomp/search