Very few foods naturally have vitamin D. Fortified foods provide most of the vitamin D in American diets. 1  Fatty fish such as salmon, tuna, and mackerel are among the best sources.  Beef liver, cheese, and egg yolks provide small amounts.
Note: To contact a Seller requesting an invoice for an item Fulfilled by Amazon: 1  Go to Your Orders. 2  Click on the Seller's name, located below the item title. 3  Click on Contact Seller in More Information. 4  Fill out the information request form.
Although Amazon lets third-parties sell products, used or brand new, through the Amazon website, certain sellers may have unclear or vague product listings. However, each seller's storefront has a contact option that you can use if you want to get more information about a particular item. If you have already purchased an item, you can contact the seller to clear up any issues about your order via the Amazon Orders panel. credit: AntonioGuillem/iStock/Getty Images.