5 Ways to Get More Vitamin D for Stronger Immunity

Discover Why The “Sunshine Vitamin” is Essential for Your Immune Health

Vitamin D does the body good. This essential nutrient is crucial for various bodily functions, such as enhancing calcium absorption for stronger bones and playing a role in muscle growth and development.1 Additionally, Vitamin D is arguably the most important nutrient for maintaining a healthy, well-functioning immune system.

Unfortunately, vitamin D deficiency has become a global health issue affecting approximately one billion people worldwide. In the United States alone, 35% of adults and around 60% of the elderly population are deficient in vitamin D.2 Meanwhile, mounting scientific evidence suggests that vitamin D may help ward off a variety of chronic conditions, such as diabetes, depression, heart disease, osteoporosis, and autoimmune diseases.3

Why is Vitamin D Essential for Your Immune Health?

Your immune system comprises an entire army of different types of immune cells that strategically work together to defend your body from anything that might cause harm. Some cell types, mainly neutrophils, patrol your body looking for foreign substances. Other cells, such as NK cells, are adept at quickly destroying potential threats. While, additional immune cells, particularly B and T cells, play a crucial role in long-term immunity.

Almost all of the immune cells in your personal army of defense have receptors for vitamin D, which helps strengthen, regulate and balance your immune system for stronger immunity when your body needs it most.4

Researchers describe the relationships between your immune system and vitamin D as indisputable. Additionally, research suggests that low levels of vitamin D are associated with the common cold and flu. Several studies have linked insufficient levels of the essential nutrient to an increased risk for respiratory tract infections.5

5 Ways to Get More Vitamin D for Stronger Immunity

1. Spend Time in the Sunshine

Vitamin D is often referred to as the 'sunshine vitamin,' and for good reason. Your body produces its own vitamin D through interactions with sunlight. Therefore, regular sun exposure is one of the most effective ways to increase your vitamin D levels. Experts suggest spending 10-30 minutes in direct sunlight on your bare skin three times per week.6 It's recommended to apply sunscreen after the initial 10-30 minutes, depending on your level of sensitivity.

However, depending on where you live, obtaining the appropriate amount of UVB rays can be quite challenging. For instance, individuals residing further away from the equator typically need to spend more time in the sun to generate sufficient levels of vitamin D.7 Moreover, for those living in colder climates, getting enough sunlight on the skin can be nearly impossible during the winter months, making it essential to obtain vitamin D from sources other than the sun.

2. Consume Fatty Fish and Cod Liver Oil

Unfortunately, vitamin D isn't naturally abundant in many common foods. However, it can be found in fatty fish and seafood such as salmon, mackerel, tuna, and halibut. Other excellent sources of vitamin D, rich in omega-3 fatty acids, include oysters, shrimp, anchovies, canned sardines, and pickled herring. For those who don't enjoy fish, another option is to take cod liver oil, which is a great source of both vitamin D and vitamin A.

3. Eat More Mushrooms.

For vegetarians, mushrooms can be a good source of vitamin D, as they produce their own vitamin D when exposed to sunlight. According to a 2021 study published in Food Science & Nutrition, a single serving of mushrooms can increase vitamin D intake by nearly 100%. The caveat is that the mushrooms themselves must be exposed to UV light, making wild mushrooms and those treated with UV light the more desirable choice.

4. Take Vitamin D Supplements

If you don't receive enough sunlight during the winter months or consume sufficient fatty fish, you may want to consider a vitamin D supplement. Studies indicate that vitamin D supplementation can help prevent the common cold, reducing the frequency and severity of symptoms of upper respiratory tract infections.8

Experts recommend opting for vitamin D3 supplements, derived from animals, over vitamin D2 supplements, which come from plants (like mushrooms). Research suggests that vitamin D3 is more effective at raising vitamin D levels.9 Meanwhile, the appropriate vitamin D dosage depends on your current levels; however, in general, the recommended dose for adults is 800–2000 IU daily.10

5. Seek Out Fortified Foods

While there aren’t many common foods that naturally contain vitamin D, this essential nutrient can be added to staple goods such as whole milk, orange juice, yogurt, and cereal. These are known as fortified foods and are often labeled as such directly on the packaging. However, if you’re not sure, you can always check the nutrition label (and watch out for excessive sugar!).

Bottom Line

Vitamin D plays a crucial role in maintaining our overall health, from supporting bone strength and immune function to potentially preventing various chronic conditions. While sunlight remains an excellent natural source, factors like geographical location and seasonal changes can limit its accessibility. Whether through fatty fish, mushrooms, fortified foods, or supplements, maintaining optimal vitamin D levels contributes to our well-being. As with any health-related decision, consulting with a healthcare professional ensures personalized guidance in navigating the best approach for individual needs.

Interested in learning about essential nutrients for your immune health? Click the button below to discover more vitamins for stronger immunity.

3 Essential Vitamins for the Immune System

1Gordon PL, et al. Relationship between vitamin D and muscle size and strength in patients on hemodialysis. J Ren Nutr. 2007 Nov; 17(6): 397-407.

2Sizar O, et. al. “Vitamin D Deficiency.” Treasure Island (FL): StatPearls Publishing; Jan. 2023.

3Wang H, et al. Vitamin D and Chronic Diseases. Aging Dis. 2017 May 2;8(3):346-353.

4Martens PJ, et al. Vitamin D's Effect on Immune Function. Nutrients. 2020 Apr 28; 12(5): 1248.

5Duval, W. “Low Vitamin D Levels Associated with Colds and Flu.” NIH Research Matters. 9 March 2009.

6Rhodes LE, et al. Recommended summer sunlight exposure levels can produce sufficient (> or =20 ng ml(-1)) but not the proposed optimal (> or =32 ng ml(-1)) 25(OH)D levels at UK latitudes. J Invest Dermatol. 2010; 130(5): 1411-1418.

7Wacker M, Holick MF. Sunlight and Vitamin D: A global perspective for health. Dermatoendocrinol. 2013; 5(1): 51-108.

8Martineau AR, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017 Feb 15; 356: i6583.

9Tripkovic L, et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. Am J Clin Nutr. 2012; 95(6): 1357-1364.

10Dědečková E, et al. Vitamin D3 Supplementation: Comparison of 1000 IU and 2000 IU Dose in Healthy Individuals. Life (Basel). 2023 Mar 16; 13(3): 808.