Does Cod Liver Oil Have Vitamin D?

Your great-grandmother may have dosed the family with cod liver oil to ward off illness and keep everyone in good health. Cod liver oil began as a folk medicine, used by cod fishermen and their families. Though Grandma may not have known why cod liver oil worked, scientists now know that cod liver oil contains vitamins A and D and essential fatty acids. Modern cod liver oil is processed to be tasteless and odorless.

History of Cod Liver Oil

Diane Wendt, associate curator with the National Museum of American History, says that cod fishermen in northern European fishing villages were probably the first to use cod liver oil as a remedy. To make cod liver oil, the fishermen put fish livers in barrels. The livers rotted, and as they rotted, they released oil. The oil was used as a lubricant and emulsion, but somewhere along the way, people began taking it as a curative and to prevent illness. This cod liver oil smelled vile and apparently tasted horrible, but it worked well enough that people continued to take it.

Vitamin D in Cod Liver Oil

The chemical structure of vitamin D was identified in the 1930s, starting with the vitamin D your body makes from sunlight. By 1936, scientists mapped the chemical structure of vitamin D-3, and at the same time, researchers identified one active component of cod liver oil as vitamin D-3.

Role of Vitamin D

Vitamin D helps your body process calcium, but it also plays a role in bolstering your immune system. A strong immune system helps you fight off infection. Your body manufactures vitamin D from sunlight, but if you spend a lot of time indoors, wear sunscreen outdoors or live in a northern climate, you may not get as much vitamin D as you need. Fortified milk and orange juice and fish oil are two dietary sources of vitamin D.

Cod Liver Oil Today

Though cod liver oil may seem like an old-fashioned remedy, it's still sold and used today. In 2001, researchers at the New York Eye and Ear Infirmary found that children who had a history of ear infections required fewer antibiotics and missed fewer days of school due to illness if they took a teaspoon of lemon-flavored cod liver oil daily with a multivitamin that contained selenium. The essential fatty acids in cod liver oil can help decrease inflammation, while vitamins A and D ward off infection. Though modern cod liver is flavored or tasteless, you can also take cod liver capsules.