Top 10 natural food sources of immunity-boosting vitamin D

Vitamin D is one of the most extensively studied nutrients. Contrary to popular belief, vitamin D is not, well, a vitamin. The body can produce its own vitamin D, so it is technically a hormone. The primary source of vitamin D is sunlight. When skin cells are exposed to sunlight, a molecule in the skin known as 7-dehydrocholesterol is converted into a crude form of vitamin D known as cholecalciferol. Various factors influence the amount of vitamin D the body produces, from the number of pigment skin cells to the strength of UV rays. This being the case, it’s difficult to judge how much vitamin D the body will produce when bathed in warm sunshine.

A growing body of scientific evidence suggests that vitamin D deficiency is linked to a host of health problems, including diabetes, heart disease and even certain cancers. By the same token, vitamin D plays a critical role in boosting the immune system. It is important to improve nutrition through a healthy diet. In order to ensure you are getting enough vitamin D, consider the following natural food sources:

1. Shrimp

Shrimp are often chastised as bottom feeders, but there is more to this crustacean than meets the eye. In addition to being an ample source of vitamin D, B3 and zinc, shrimp are often recommended for people trying to lose weight. They also contain good cholesterol, which can help combat cancer.

Other nutrients in shrimp include vitamins A, E and B6, as well as magnesium, iron, zinc, sodium (salt) and copper. Shrimp even have traces of vitamin C in their meaty flesh.⁽¹⁾

2. Natural yogurt

There are many different types of yogurt that contain varying amounts of vitamin D. While many yogurts are loaded with fats, sugars and preservatives, natural yogurt made from raw or organic milk is still available. Studies have shown that the vitamin D in fortified yogurt is better for bone absorption than non fortified equivalent foods. Yogurt is easy to incorporate into your diet, either with breakfast or as a snack. It’s important to note that not all yogurts are created equal, however. Just because a yogurt is high in vitamin D does not mean it meets other nutritional standards. Fortified yogurt is the best yogurt to help meet your daily dose of vitamin D and other nutritional needs.⁽²⁾

3. Pastured eggs

Pastured eggs are recognized as a good source of protein and less well recognized as a good source of vitamin D. Egg yolks are the source of vitamin D in eggs. The recommended daily dose of vitamin D is 600 IU. The average egg has about 20 IU per 100 grams; however, different types of eggs contain different amounts of vitamin D. Reports suggest that pastured eggs have four to six times as much vitamin D as supermarket eggs. This means that just two pastured eggs give you anywhere from 63 to 126 percent of the recommended daily dose of vitamin D! While pastured eggs shouldn’t be relied on as a primary source of vitamin D, they are an excellent secondary source for this important fat soluble.⁽³⁾

4. Mushrooms

Mushrooms that are exposed to sunlight are an excellent source of vitamin D. You can increase the amount of vitamin D in mushrooms simply by placing them in the sunlight. Research from the University of Boston found that mushrooms provide as much vitamin D as supplements that contained vitamin D2 and D3. In addition, the researchers found that mushrooms make, store and preserve vitamin D2 in a way that mirrors how human skin makes vitamin D when exposed to sunlight. Shitake mushrooms and button mushrooms are a particularly good source of vitamin D. Eating mushrooms loaded with vitamin D is a sure means to boosting your immune system and keeping various illnesses at bay.⁽⁴⁾

5. Wild salmon

Wild salmon is prized for its omega-3 fatty acids, but did you know that it is also a great source of vitamin D? A Boston University team discovered that wild salmon had a whopping 988 IU of vitamin D per 3.5 oz serving. In contrast, the researchers found that farmed salmon had only 25 percent of the vitamin D of the wild salmon. Farmed salmon usually has more toxins than wild salmon, so it’s best avoided anyway. Small servings of wild salmon can help maintain strong bones, boost the immune system and decrease the risk of heart disease.⁽⁵⁾

6. Sardines

Sardines are teeming with Vitamin D. A small can of sardines provides approximately 70 percent of your recommended dietary intake of vitamin D. The vitamin helps keep your bones strong, and enables the body to absorb calcium from food more efficiently. They are also an ample source of protein and omega-3 fatty acids. You can add sardines to a pizza, salad or wholewheat pita. Sardines that have the lowest mercury are usually skinless and boneless.⁽¹⁰⁾

7. Mackerel

Mackerel is another cold water fish with plentiful amounts of vitamin D. This immune boosting fish delivers approximately 547 IU of vitamin D per three-ounce serving. Mackerel is also an excellent source of protein, omega-3 fatty acids and vitamin A. As a source of vitamin D, mackerel can help strengthen the immune system and improve the body’s overall function. Small doses of mackerel are generally regarded as safe; however, the King mackerel is a large predatory fish with heavy metal pollutants that should be avoided. Nevertheless, feel free to snack on small amounts of mackerel.⁽⁹⁾

8. Eel

Did someone order eel? While not a typical restaurant dish, eel is another freshwater creature that is an excellent source of vitamin D. Just three ounces of eel delivers 792 IU of vitamin D. Like other sea creatures, eel is chock full of nutrients, including vitamins B1, B2, B3, B6, folate, B5 and B12. These vitamins help protect the immune system, support a healthy heart and improve vision. In addition, eel has zero sugar and is low in sodium. This nutrient dense fish can strengthen bones, build muscle mass, lower cholesterol and ward off various cancers. Word of caution: Eel is a meaty fish with ample amounts of fat, so it is best to eat it in small doses. It is often used in sushi or can be consumed as a capsule.⁽⁶⁾

9. Herring

Herring is enriched with Vitamin D, and is found in both Scandinavian cuisine and Japanese cooking. A single serving of pickled herring provides more than twice the amount of vitamin D the body requires. Along with its immune system boosting powers, research suggests that herring can help improve fertility in men. It’s also a rich supply of fatty acids that maintain a healthy heart and improve brain function. You can add herring to sandwiches and salads, or eat it whole as a fillet.⁽⁷⁾

10. Cod liver oil

Cod liver is the best source of vitamin D in all the land and sea. Eating fish does not provide the amount of nutrients found in cod liver oil. A small amount goes a long way; a tablespoon of cod liver oil provides 1,360 IU’s of vitamin D per serving. The fish oil can be used as a remedy for muscle aches, heart disease, high (bad) cholesterol and diabetes, and even help prevent upper respiratory tract infections. It also contains high amounts of EPA and DHA, two amino acids in omega-3 fats that play an essential role in the proper functioning of both the brain and nervous system. Adding excessive amount of cod liver oil to your diet is not necessarily better. A capsule or tablespoon of cod liver oil is more than enough to ensure you are consuming your recommended daily dose of vitamin D.⁽⁸⁾

Vitamin D is a powerful immune system controller. Most, if not all, cells in the body contain vitamin D receptors. Since it acts as a regulator, vitamin D enhances the functioning of the immune system. This is why it is so important to not become deficient in vitamin D. Although vitamin D isn’t found in many foods, eating these foods is a sure way to obtain all the vitamin D you need.

Sources include:

(1) Health.com

(2) NCBI.NLM.NIH.gov

(3) MotherEarthNews.com

(4) EurekAlert.org

(5) SpryLiving.com

(6) Storify.com

(7) LiveStrong.com

(8) AltMedicine.About.com

(9) GlobalHealingCenter.com

(10) HealthyEating.SFGate.com