Home Products Most Popular Contact
No items in your cart.
The page below is a sample from the LabCE course Vitamin D. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Vitamin D (online CE course) »
How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 129 CE courses, most popular
$95 Add to cart
Pick Your Courses
Up to 8 CE hours
$50 Add to cart
Individual course$20 Add to cart


There are very few foods in nature that contain vitamin D. The best sources are fatty fish such as salmon, tuna, and mackerel, as well as fish liver oil. Small amounts are found in beef liver, cheese, and egg yolks. Vitamin D in these items is primarily in the form of vitamin D3 and its metabolites. Some types of mushrooms can provide vitamin D2 in small amounts.
In the 1920's vitamin D was recognized for its role in preventing rickets. It was after this time some foods began to be fortified with the vitamin (milk, cereal, etc.) to help prevent this disease. To this day, fortified foods provide most of the vitamin D in the American diet. For example, almost all of the U.S milk supply is voluntarily fortified with 100 IU/cup of vitamin D. In Canada, milk is fortified by law with 35 - 40 IU / 100 mL, as is margarine at greater than or equal to 530 IU/100 g. Vitamin D3, or cholecalciferol, is the form of vitamin D found in milk.