12 Foods High in Vitamin D: Are They Enough?

Did you know that vitamin D is also known as the "sunshine vitamin"? That's because, unlike any other vitamin, our bodies make vitamin D naturally when our skin is exposed to the sun.

In general, as humans, we depend on our diet to get our necessary supply of vitamins and minerals. However, this nutrient is one of the few exceptions—it can actually be synthesized in our bodies!

Despite this fact, vitamin D deficiency is widespread. According to experts, 42% of Americans and about 1 billion people worldwide are vitamin D deficient.

Some experts believe vitamin D deficiency is the result of low intake of the nutrient coupled with behaviors that limit UV-light exposure, such as reduced time outdoors, the use of sunscreen, and the use of protective clothing to fully cover the skin.

Fortunately, there are other ways to make sure you meet your vitamin D needs, including foods and supplements. However, food sources of vitamin D are limited.

Let's dive in and explore the best ways to ensure you're getting enough of this critical vitamin.  

What is vitamin D?

Vitamin D is a nutritional superstar! It is a fat-soluble vitamin that serves many vital functions in our body. It is also classified as a hormone, which means it is involved in supporting several systems throughout the body.

Most of us associate vitamin D with bone health, and that's definitely true! It supports calcium absorption, helping to maintain strong bones.

However, this nutrient is not just critical for healthy bones—it has several other important functions in the body. It is a key player in maintaining cardiovascular health, immune system health, brain health and kidney health, to name a few.

There are 3 ways we can get vitamin D: from the sun, from food and from dietary supplements.

How much vitamin D do you need?

The recommended daily allowance (RDA) for vitamin D varies depending on age. The current guidelines are:

• Infants 0-12 months: 400 IU (10 mcg)
• Children and adults 1-70 years: 600 IU (15 mcg)
• Adults > 70 years: 800 IU (20 mcg)

The RDA provides the daily amount needed to avoid vitamin D deficiency, maintain bone health and normal calcium metabolism in healthy people, and support immune health. However, many experts, including Life Extension, recommend much larger amounts—for most people, between 5,000-8,000 IUs (125-200 mcg) daily.

What foods have the highest source of vitamin D?

There are very few foods naturally high in vitamin D. They include fatty fish, eggs and mushrooms. However, many foods are fortified with vitamin D. Fortified foods actually provide most of the vitamin D in the American diet.

Fortified foods are those that have had nutrients added to them that don't naturally occur in that food. Many foods in the U.S. are fortified with vitamins and minerals—including milk, which is fortified with D.

Here's a list of the top vitamin D-containing foods from both natural and D-fortified sources:

1. Salmon

Fresh salmon is a nutrient-packed food that contains about 14.2 mcg/570 IU of vitamin D per 3-ounce serving, plus it's a great source of omega-3s. When choosing salmon, try to choose wild-caught over farmed salmon when possible. Some studies show that wild salmon may contain much higher amounts of D than farmed salmon.

2. Rainbow trout

A 3-ounce serving of this D-rich fatty fish provides 16.2 mcg/645 IU, which is more than 100 percent of your daily requirement.

3. Swordfish

This fish contains 14.1 mcg/564 IU of vitamin D per 3 ounces. Keep in mind that while swordfish is rich in D and omega-3 fatty acids, it can also contain high levels of mercury, which should be avoided. While most people can safely consume swordfish in moderation, certain populations should avoid it, such as women who are pregnant or breastfeeding and young children.

4. Canned tuna

Canned fish is a high-protein source of vitamin D that is typically less expensive and more widely available than fresh fish. Canned tuna can also be high in mercury, so choose light (skipjack) tuna in water over albacore as it contains significantly less mercury and more vitamin D—1 mcg/40 IU in 3 ounces. Canned sardines in oil are also an excellent option, with two sardines providing 1.2 mcg/46 IU.

5. Cod liver oil

One tablespoon of cod liver oil packs a whopping 1360 IU of D as well as heart-healthy omega-3 fatty acids!

6. Mushrooms

Low-fat, nutrient-dense mushrooms are rich in vitamins, minerals and antioxidants. A recent meta-analysis found that mushroom consumption was associated with healthy longevity. Except for fortified foods, mushrooms are the most popular vegetarian source of vitamin D. Mushrooms synthesize vitamin D when exposed to UV light, just like humans do. However, mushrooms produce vitamin D2 rather than the D3 we produce. Commercially grown mushrooms are typically grown in the dark and exposed to UV light after harvest to boost their vitamin D content. A cup of cremini mushroom exposed to UV light contains 1110 IU. In contrast, mushrooms not UV-exposed typically contain less than 40 IU.

7. Eggs

One large egg provides 1.2 mcg/44 IU of vitamin D. Keep in mind that this nutrient is in the egg yolk, not the white. So don't ditch those egg yolks! Free-range eggs, which come from chickens that are allowed to roam outdoors, contain higher amounts of vitamin D than eggs from chickens kept indoors.

8. Fortified milk

Contrary to what many may think, pasteurized dairy milk does not naturally contain much vitamin D. Almost all of the U.S. milk supply is fortified with about 120 IU per cup. There is much debate whether dairy milk or plant-based milk is better for you. Either way, your needs will be covered because plant milk alternatives like soy milk, almond milk and oat milk are often fortified with similar amounts of D.

9. Fortified orange juice

Enjoying a glass of orange juice to start your day is another good way to boost your D intake. One cup of fortified orange juice provides about 100 IU.

10. Fortified yogurt

D-fortified yogurt is a convenient, nutrient-packed snack that provides calcium, protein and gut-friendly probiotics.

11. Fortified cereals

Some ready-to-eat cereals and instant oatmeal products are also fortified (about 80-100 IU per serving). And if you enjoy your breakfast cereal with some milk, you'll be getting a double dose!

12. Fortified tofu

Not all tofu is fortified, but those brands that are provide around 100 IU per 3.5 ounces. Fortified tofu can be a good source of this nutrient for vegans or vegetarians who may struggle to get enough vitamin D.

What are other sources of vitamin D?

The biggest natural source of vitamin D is the sun! Our bodies are able to synthesize vitamin D through exposure to sunlight. Ultraviolet exposure converts cholesterol in our skin to vitamin D3. This D3 enters the blood and is transported to the liver and kidneys, where it is converted to its bioactive form (calcitriol).

Just 30 minutes of sunlight exposure may sometimes provide what you need! So consider getting outside for a quick walk every day to boost your vitamin D levels. One study in Norway found that if Caucasians spent 30 minutes in the midday summer sun, they experienced 25-hydroxy-vitamin D levels equivalent to taking 10,000-20,000 IUs.

Keep in mind, the amount of vitamin D we get from sun exposure varies considerably depending on several factors, including geographic latitude and skin color. Sunlight is generally weaker in Northern latitudes, leading to less D synthesis. Also, people with naturally darker skin tones generally need a lot more sun exposure to synthesize vitamin D because melanin inhibits the skin's ability to produce D3 from sunlight. Research shows that black-skinned individuals will have to spend 6 times longer in the sun than light-skinned ones to achieve a similar level of serum 25-hydroxyvitamin D concentrations.

Can you get enough vitamin D from food?

Since there are relatively few good food sources of vitamin D, it is difficult to get enough vitamin D from food alone. For most people, the best way to get your RDA is through a combination of sunlight, food and dietary supplements.

To achieve optimal blood levels of vitamin D, most people will need to take between 5,000-8,000 IUs (125-200 mcg) daily. If you're considering taking a dietary supplement, it's important to know your vitamin D status and to have your vitamin D levels monitored.

The D found in supplements comes in two different forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Both increase vitamin D levels but most evidence indicates that D3 raises blood levels of the active form of vitamin D more efficiently than D2.

All D2 supplements come from non-animal sources, while most D3 supplements come from animal sources. However, there are vegan vitamin D3 supplements available (that are made from algae or lichen) if you are following a plant-based diet.

Most people can benefit from taking a vitamin D supplement either alone or in combination with other supplements like vitamin K, as vitamin D3 and K2 work together to support bone health. 

Is it possible to get too much vitamin D?

Yes, vitamin D can be harmful when levels become too high. That's because it, like other fat-soluble vitamins, is stored in the body (mainly in the liver and adipose tissue) much longer than water-soluble vitamins.

Vitamin D toxicity is rare but when it occurs, it's typically from taking extremely high doses of supplements for a prolonged time rather than from food or sun exposure. This is why it is important to monitor your vitamin D levels and speak with your healthcare provider before starting any supplement routine.

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