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You’ve probably heard that vitamin D is important. But what benefits does it provide the body? Are there other ways to get your daily dose? The sun is the best source of vitamin D, but surprisingly it's not the only source.


June 12, 2023

Whether you live in a state with year-round sunny days like Florida, or endure long, grey winters in Pennsylvania, vitamin D deficiency is more common than you think. In fact, about 50% of the worldwide population has insufficient levels of vitamin D and in the United States, 35% of adults have the deficiency.1

Vitamin D is known as the vitamin the sun gives you, but some people will not be able to get enough from the sunlight alone. Sunlight is a natural source of vitamin D. However, excessive exposure to the sun can lead to skin damage, sun poisoning and increase the risk of skin cancer. Therefore, it is important to find alternative ways to get enough vitamin D without spending too much time in the sun. We’re exploring the importance of vitamin D and providing you with some easy and effective sun-free ways to get enough of this essential nutrient.

Why is Vitamin D Important?

woman dancing next to window with sun coming in the room

Vitamin D is one of many vitamins your body needs to stay healthy. It plays a crucial role in maintaining the balance of calcium in your blood and bones and in building and maintaining them. Your body can only absorb calcium (the primary component of bone) when vitamin D is present. Beyond your bones, vitamin D is also a key factor in cell growth, supporting the immune system to fight infection, disease and inflammation.2 How much vitamin D do you need for optimal health? In the United States, current guidelines suggest that consuming 400–800 International Units (IU) of vitamin D should meet the needs of 97%–98% of all healthy people.3

Vitamin D Deficiency

The are several factors that can contribute to vitamin D deficiency. Since your body produces it naturally when it’s directly exposed to sunlight, the amount of vitamin D your skin makes depends on many factors. Some include:2

  • Where you live, your job and how much sun you’re exposed to as production might decrease or be completely absent during the winter months.
  • Sunscreen: While important to prevent skin cancer, also can decrease vitamin D production.
  • Having a darker skin tone: People with darker skin have higher levels of melanin which can reduce your skin’s ability to absorb vitamin D through sunlight.
  • Medical conditions: Conditions that affect the digestive system, such as celiac disease, Crohn’s disease and cystic fibrosis can interfere with the body’s ability to absorb or use vitamin D.

These factors can increase your risk of vitamin D deficiency. That’s why it’s important to get some of your vitamin D from non-sunlight sources.

What are the Symptoms of Vitamin D Deficiency?

A deficiency can be difficult to notice because symptoms may not occur for several months or years. Most people with vitamin D deficiency don’t notice any symptoms. Possible symptoms might include:

  • Fatigue
  • Bone pain
  • Muscle weakness, muscle aches or muscle cramps
  • Mood changes, like depression
  • Difficulty thinking clearly and cognitive impairment, often stemming from accompanying sleep difficulties

Foods with Vitamin D

salmon eggs and beans sitting on a table with a sign that says vitamin d

Fatty Fish and Seafood

Fatty fish and seafood are among the foods highest in vitamin D, though exact vitamin content may vary depending on the type and source. They are also rich in omega-3 fatty acids. Some examples of fish that are good sources (high IU) include:4

  • Salmon: One 3-ounce serving of cooked salmon contains about 383-570 IU
  • Trout: One 3-ounce serving of cooked mackerel contains about 645 IU
  • Tuna: One 3-ounce serving of canned tuna contains about 150-250 IU
  • Sardines: One 3-ounce serving of canned sardines contains about 164 IU

It is important to note that while fatty fish are an excellent source of vitamin D, they can also be high in mercury, which can be harmful in large amounts.

Fortified Food

Manufacturers add vitamin D to many commercially available foods. People describe these foods as being fortified with vitamin D, or other nutrients. Examples include:4

  • Cow’s Milk: Most milk in the United States is fortified with vitamin D, with one cup providing about 25% of the recommended daily intake of vitamin D.
  • Hot and Cold Cereal: Some cereals are fortified with vitamin D, with the amount varying depending on the brand and type. Oatmeal is often fortified with a 1/2 cup providing up to 120 IU depending on the variety.
  • Yogurt: Some brands of yogurt are fortified with vitamin D, with the amount varying depending on the brand and type.
  • Non-dairy beverages: Plant-based milk alternatives, such as soy, oat, hemp and almond milk plus orange juice are often fortified providing about 25% of the recommended daily intake of vitamin D similar to cow’s milk.

Due to inconsistent standards between countries, checking a food’s ingredient list or nutrition label remain the best way to verify whether it’s fortified in vitamin D and how much it contains.


Mushrooms are the only natural vegetarian source, and like us, they also make their own vitamin D. When mushrooms are exposed to UV light, they can produce vitamin D2, which is the same form of vitamin D that is found in fortified foods and supplements. Some varieties of mushrooms that are particularly high in vitamin D2 include:5

  • Shiitake mushrooms
  • Button mushrooms

It is important to look for mushrooms that have been specifically grown or exposed to UV light to maximize their vitamin D content.

Egg Yolks

Vitamin D is found in the yolk of the egg only. Eggs also contain all your essential amino acids and are a great source of choline and healthy fats. When possible, choose free-range or pastured eggs, as they contain 4 to 6 times more vitamin D. On average, one large egg yolk contains about 44 IU. 3,6

Cod Liver Oil There are numerous benefits of cod liver oil — It is rich in healthy fats, vitamins, and antioxidants. Most cod liver oil is extracted from the liver of Atlantic cod and a single tablespoon can provide 1,360 IU of vitamin D.3 Cod liver oil is a whole food, like olive oil or coconut oil, and it should taste pleasant like fish, but not overtly fishy.

Not Feeling Food?

hand holding a vitamin d supplimentSupplements are a convenient and effective way to ensure that you are getting enough of this important nutrient, especially if you are not able to get enough from sunlight or food. There are two main types of vitamin D supplements:3

  • Vitamin D3 is the most effective form of vitamin D supplement because it is the same form of vitamin D that is produced naturally in the body when the skin is exposed to sunlight. These supplements are available in many forms, including capsules, tablets and liquid drops.
  • Vitamin D2 supplements are also available, but they are less effective than vitamin D3 supplements because they are not as well absorbed by the body. Vitamin D2 supplements are typically found in fortified foods and some supplements. 

MedExpress Pro Tip: Vitamin D is fat-soluble; consuming your soft gel with fatty foods may help increase its rate of absorption.

When choosing a vitamin D supplement, it is important to consider the dosage, as well as any potential interactions with other medications or supplements you may be taking. It is important to talk to your healthcare provider before starting any supplements to determine the right dosage for you.

The amount of vitamin D you need depends on what your vitamin D level is currently. Rather than guess how much you need, consider getting your levels checked so you can adjust your intake to optimize your level and discuss supplementation with your health care provider. Getting enough vitamin D can go a long way to boosting your health.


1 National Library of Medicine: Vitamin D Deficiency. Last Updated February 19, 2023. Accessed March 23, 2023.

2 Mayo Clinic: Vitamin D. Last updated. February 09, 2021. Accessed March 23, 2023.

3 National Institute of Health: Vitamin D. March 23, 2023.

4 DGA: Food Sources of Vitamin D. Accessed April 7, 2023.

5 Center for Nutrition Studies: How To Get Your Vitamin D From Mushrooms. Updated October 14th, 2021. Accessed April 7, 2023.

6 National Library of Medicine: Free-Range Farming. Accessed April 7, 2023.

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