Fatty fish, egg yolks, fortified milk, UV-treated mushrooms, and cod liver oil are the richest sources of vitamin D. Your body also makes it from sunlight, which is actually the primary source for most people. But surprisingly few foods contain vitamin D naturally, so knowing exactly where to find it matters.
Fatty Fish: The Best Natural Source
No food delivers vitamin D as reliably as fatty fish. Wild-caught salmon leads the pack at roughly 988 IU per 3.5-ounce serving, which is well above the 600 IU recommended daily intake for most adults. Farmed salmon contains significantly less, averaging around 240 IU for the same portion. That’s a fourfold difference driven by the diet and environment of the fish.
Farmed trout is a solid middle ground at about 388 IU per 3.5 ounces. Canned pink salmon delivers around 493 IU per 3-ounce serving, making it one of the more convenient and affordable options. Spanish mackerel contains roughly 248 IU per 3 ounces raw, though vitamin D content varies widely between mackerel species.
If you eat fish two to three times per week, you can cover a large share of your vitamin D needs from food alone, something that’s difficult to do with almost any other dietary pattern.
Eggs and the Pasture-Raised Difference
Egg yolks contain vitamin D, but the amount depends heavily on how the hens were raised. Eggs from hens kept entirely indoors contain about 3.8 micrograms of vitamin D per 100 grams of yolk. Eggs from hens with outdoor access contain three to four times more, averaging 14.3 micrograms per 100 grams. The reason is straightforward: hens exposed to sunlight produce more vitamin D themselves, and it ends up in the yolk.
A single conventional egg yolk typically provides around 40 IU, so eggs alone won’t meet your daily needs. But pasture-raised eggs can contribute meaningfully, especially as part of a meal that includes other sources.
Mushrooms: The Only Plant Source
Mushrooms are the only non-animal food that naturally contains vitamin D, and only when they’ve been exposed to UV light. Untreated portabella mushrooms contain a negligible 10 to 11 IU per 100 grams. The same mushrooms exposed to UV light for just 15 to 20 seconds jump to 446 IU per 100 grams, with some batches reaching as high as 752 IU.
Look for packaging that says “UV-treated” or “high in vitamin D.” Many grocery stores now carry these, and the label will typically list the vitamin D content. One important distinction: mushrooms produce vitamin D2, while animal sources and sunlight provide D3. Research published in The Journal of Clinical Endocrinology & Metabolism found D3 is more than three times as potent as D2 at raising blood levels over 28 days. Both forms are absorbed equally well in your gut, but D3 stays active in your bloodstream much longer. Mushrooms are still a worthwhile source, especially for people on plant-based diets, but D2’s lower potency means you need more of it to get the same effect.
Cod Liver Oil
A single teaspoon of cod liver oil delivers about 400 IU of vitamin D3, roughly two-thirds of the daily recommendation for most adults. Many people in Scandinavian countries use a full tablespoon (15 ml), which provides considerably more. Cod liver oil also contains omega-3 fatty acids and vitamin A, making it one of the most nutrient-dense single sources available. The taste is strong, though flavored versions and capsules have made it more palatable.
Fortified Foods
Because so few foods contain vitamin D naturally, many countries fortify staple products. In the United States, cow’s milk is routinely fortified to provide around 100 to 120 IU per cup. Most plant-based milks (soy, almond, oat) are fortified to similar levels, though amounts vary by brand. Breakfast cereals, orange juice, and yogurt are also commonly fortified, typically providing 50 to 200 IU per serving.
Fortified foods tend to deliver modest amounts per serving. You’d need to drink five or six cups of fortified milk daily to reach 600 IU from that source alone. They work best as part of a broader strategy that combines several sources.
Sunlight: Your Body’s Built-In Source
Your skin produces vitamin D3 when exposed to UVB rays from the sun. For most people, this is actually the largest source. A 2024 study modeling UV exposure in the Mediterranean found that producing 1,000 IU per day requires roughly 5 to 25 minutes of midday sun, depending on skin tone. People with very fair skin (Type I) need about 5 minutes; those with very dark skin (Type VI) need about 25 minutes. These estimates assume exposed arms and face without sunscreen between 10 a.m. and 4 p.m. from March through October.
Season and latitude matter enormously. Research modeling sun exposure in Japan found that at a mid-latitude city, producing just 220 IU took only 3.5 minutes at noon in July but 22 minutes at noon in December. At 9 a.m. in December, it took nearly two hours. If you live above about 35°N latitude (roughly the level of Atlanta or Los Angeles), your skin produces little to no vitamin D from sunlight during winter months.
Darker skin tones require 2.5 to 3 times the UV exposure of lighter skin to raise blood levels by the same amount, because melanin absorbs the UV radiation that triggers production. Sunscreen also blocks synthesis, though most people don’t apply it thickly or consistently enough to eliminate production entirely.
How Much You Actually Need
The recommended daily intake is 600 IU for everyone between ages 1 and 70, and 800 IU for adults over 70. Infants need 400 IU. These recommendations assume minimal sun exposure, so they’re designed to be met through food and supplements.
Most adults fall short. The gap is largest during winter, in people with darker skin, and in those who spend most of their time indoors.
Cooking Affects How Much You Keep
How you cook vitamin D-rich foods changes how much of the nutrient survives. Boiling eggs retains 86 to 88% of the vitamin D. Frying retains a similar 82 to 84%. Baking is harder on it: eggs and margarine baked in an oven for 40 minutes retain only 39 to 45%. Bread baked with added vitamin D retains 69 to 89%, depending on the type of flour.
The takeaway is practical: quick cooking methods like frying, poaching, and boiling preserve vitamin D better than long oven baking. If you’re counting on eggs or fortified bread as a source, the preparation method makes a real difference.