About 35 percent of American adults are deficient of vitamin D. The recommended daily intake for vitamin D is around 800 international units (IU) or 20 micrograms. Here are some ways to help you increase your vitamin D intake year-round through dietary changes:

Eat more fish. Salmon and tuna, even canned tuna, are rich in vitamin D, says Kristi Ruth, a registered dietitian. Beef liver, sardines, and herring are other good sources.

Eat whole eggs. Egg yolks are rich in vitamin D, so it is best to eat the whole egg instead of just the whites.

Include mushrooms. According to a study published in the journal Nutrients, putting mushrooms out in sunlight for 15 minutes to two hours can increase their vitamin D content by exposing them to ultraviolet light.

Opt for fortified cereals and orange juice. General Mills doubled the vitamin D content in many of its popular Big G cereals, including Cheerios and Cinnamon Toast Crunch. To get the most vitamin D from orange juice, pair it with a fat source, says Ruth.