When the pandemic started, one of the daily reminders health professionals were advising the public was to take care of and boost their immune system. Since a deadly virus was going around, having a strong barrier that protects you from these invaders can do wonders in keeping you healthy.

To help boost immunity, people have been turning to different vitamins and supplements, such as vitamin D. For many years, this vitamin has been known for its benefits in bone health1 as it has a vital role in preventing osteoporosis. However, new studies are surfacing about its potential advantages in helping the immune system and, possibly, preventing serious illnesses like COVID-19.

Can vitamin D help COVID prevention? What exactly is vitamin D? How can it provide amazing health benefits? Read on below to find out.

What is Vitamin D?

Contrary to popular belief, vitamin D is not a vitamin. It’s a prohormone2 or a substance in the body that gets converted into a hormone.

Your kidneys produce the vitamin D hormone, which helps control blood calcium concentration and affects the immune system. When your blood calcium levels are at an ideal point, your bones mineralize and become healthy and strong.

Most of the vitamin D you need, your body makes for itself. Only 10% of required vitamin D2 comes from food such as oily fish and dairy products. There are other names for vitamin D, like cholecalciferol, calcitriol, calcidiol, ergocalciferol, and the sunshine vitamin.

Vitamin D and General Immunity

Vitamin D has immunoregulatory and anti-inflammatory properties3, which help with your body’s innate and adaptive immune functions.

Innate immunity is immunity you’re born with. It’s the first line of defense and removes immediate infectious threats. Meanwhile, you get adaptive (or acquired) immunity throughout your life, and it’s your second line of defense.

Research4 has found that all cells in your immune system (innate and adaptive) have vitamin D receptors. It means that vitamin D supports the functions of your overall immune system5.

When your body lacks vitamin D, you become more susceptible to numerous illnesses, such as different respiratory diseases6 and COVID-19. People with vitamin D deficiency are more vulnerable to immune-related disorders7, infections, and diseases. Lack of vitamin D can also lead to decreased lung function, which can add to more respiratory complications.

How can you be at risk for vitamin D deficiency?

The main causes of vitamin D deficiency are not consuming enough vitamin D, not absorbing/metabolizing vitamin D, and not spending ample time outdoors in ultraviolet B (UVB) sunlight.

Other specific factors8 can affect your vitamin D supply, including:

  • Diet – You don’t eat enough vitamin D-rich foods like cereals and fortified dairy products.
  • Lifestyle factors – You don’t expose your skin to sunlight because of work, lack of neighborhood outdoor space, or clothing limitations of your culture or religion.
  • Absorption problems – You have a nutrient absorption condition like celiac disease or Crohn’s disease.
  • Pollution – You live in a highly polluted area where air particles block UVB rays and prevent them from reaching your skin.
  • Skin type – If you have darker skin, you may not be getting enough sunlight to produce vitamin D, as people with darker skin need more sunlight exposure. If you have lighter skin, you may be avoiding the sun as protection from skin damage.

Other contributory factors include pregnancy, kidney and liver health, age, obesity, smoking, medications, and geographical factors.

How Can We Get More Vitamin D?

To help prevent vitamin D deficiency, you should get a healthy amount of vitamin D into your system by incorporating certain practices, such as:

1. Spending time under the sun

Expose your skin to sunlight for about 10–15 minutes every other day. When exposed to UVB radiation, a type of cholesterol in your skin converts into vitamin D. Vitamin D from the sun9 circulates through your body twice as long as vitamin D from supplements or food. However, avoid too much sun exposure during the peak hours of 10 am to 4 pm as too much UV radiation can increase your risk for skin cancer.

2. Eating more foods rich in vitamin D

If your lifestyle doesn’t permit you to be outside and soak up some sun, you could make up for your vitamin D intake by adjusting your diet. Some vitamin D-rich foods10 are fatty fish and seafood, mushrooms, egg yolks, cow’s milk, ready-to-eat cereals, tofu, and orange juice.

3. Taking vitamin D supplements

A simple way to get sufficient vitamin D levels is by taking vitamin D supplements and multivitamins. You can ask your doctor for recommendations or purchase one yourself.

Make sure to do your research and buy high-quality supplements and multivitamins in the Philippines. It is best to talk to a medical professional to know your current vitamin D levels and get a guided dose.

4. Getting a UV lamp

There are lamps available in the market today that can emit UVB radiation. This light can help boost your vitamin D levels11, similar to how sunlight does it. A UV lamp can be a helpful device if you can’t regularly go outside or break a window open. However, these devices can be a bit expensive.

Boost Your Immune Defense

As of this writing, there is still no cure for COVID-19. The best thing for you to do to protect yourself from different illnesses and diseases is to strengthen your immune system. When your immune system is healthy, you won’t easily get sick. A way to ensure that your immune system is in tip-top shape is to keep your vitamin D intake sufficient.

You can raise your vitamin D levels in different ways, either by UVB exposure, a vitamin D-rich diet, or vitamin D supplementation.

If you’re looking into taking vitamins to boost your immunity, you can always order your vitamins and supplements at Mediclick, an online drugstore for Filipinos. You don’t have to wait long to improve your immune system as Mediclick offers fast next-day delivery.




  1. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
  2. https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/vitamin-d
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6305614/
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/
  5. https://askthescientists.com/vitamin-d-immunity/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2759054/
  7. https://pubmed.ncbi.nlm.nih.gov/21527855/
  8. https://www.medicalnewstoday.com/articles/318060#causes
  9. https://pubmed.ncbi.nlm.nih.gov/22629085/
  10. https://www.healthline.com/nutrition/9-foods-high-in-vitamin-d
  11. https://pubmed.ncbi.nlm.nih.gov/27834434/