What role does vitamin D play in immune function?

What role does vitamin D play in immune function?

Vitamin D supplements are gaining popularity as a vital supplement for your health. It’s supposed to be good for everything from preventing cancer and dementia to avoiding infections and heart disease.

“Unfortunately, many supposed benefits of vitamin D supplements remain unproven. Yet, millions of people take vitamin D regularly, thinking it will help prevent a wide range of illnesses, including certain autoimmune conditions. But does it? A new randomized, controlled study published in the BMJ looks closely at that question”, writes Robert H. Shmerling, M.D for Harvard Health Education publication.

Is vitamin D beneficial for the immune system?

National Institute of Health (NIH) states that Vitamin D is considered a fat-soluble prohormone which is involved in many aspects of our wellbeing and regulatory functions just like a hormone. Everyone is aware that calcium absorption and bone health are major part of vitamin D benefits. However, most people may not know that Vitamin D is also involved in control of inflammation and immune response. Research has shown that vitamin D can interact with immune cells, affect genes that regulate inflammation, and alter the response of the immune system.

The BMJ study drew on data gathered during a large trial published several years prior. More than 25,000 older adults were randomly assigned to take 2,000 IU of vitamin D or an identical placebo (inactive pill) daily. The researchers reported that 123 people taking vitamin D developed autoimmune disease, compared with 155 people in the placebo group. This represents a 22% reduction. The overall risk reduction for developing an autoimmune disease fell from about twelve people in 1,000 to 9.5 people in 1,000.

Rheumatoid arthritis, polymyalgia rheumatica, and psoriasis were the most common conditions. No single autoimmune disease was reliably prevented by vitamin D supplementation. Only when the numbers of all the autoimmune diseases were combined did researchers see a benefit. The benefit of vitamin D was more obvious when only the final three years of the study were analyzed. This suggests that it takes a while to benefit from a daily supplement.

This randomized study is among the best to explore the impact of vitamin D supplementation on the risk of developing autoimmune disease. Overall conclusions are difficult to take from a study that based itself on patient self-reporting and average age of participants involved was 67 years of age. However, the risks of daily vitamin D are minimal and hence the benefits of daily supplement to keep you healthy may outweigh any negative impact.

Is it better to take vitamin D2 or D3?

To determine the key differences between both types of the supplement, the University of Surrey recruited 335 women between the ages of 20 and 64 who were based in the United Kingdom and randomly assigned them to a group. Some of the participants took 15 micrograms or 600IU of vitamin D2 a day, while others took the same amount of D3. There was also a placebo group that took neither D2 nor D3. The researchers examined the effects of vitamin D over a 12-week period during the winter months.

The result? Vitamin D3 was more effective at increasing vitamin D levels in the bloodstream than D2. They also found that the group who took D3 had a stronger immune system response to bacterial and viral infections, while D2 has the opposite effect. Additionally, researchers believe that D2 may deplete D3, as the D2 supplement group had less D3 in their blood than the placebo group did. "We know that to take a vitamin D2 supplement actually displaces the normal, the native D3 from your body," Colin P. Smith, an author of the study and a professor of genomics at the University of Surrey in the U.K., told Inverse. "So, by taking a vitamin D2 supplement, you could be making yourself vitamin D deficient, certainly in relation to some pathways in the body."

When is The Best Time to Take My Vitamin D Supplement?

If you are taking your vitamin D3 in pill form, experts recommend taking the pill with a full meal – preferably a fatty meal – to maximize absorption. If you take under the tongue soft molded tablets (sublingual) vitamin D3 tablets, you do not need to worry about any of the above since it absorbs under your tongue and directly into your bloodstream. No need to plan a fatty meal or worry about an upset stomach.

There is a debate about the best time of day to take Vitamin D3 – there is some research that suggests Vitamin D3 may negatively impact your sleep. Until further research is available, we recommend you consume your Vitamin D3 supplements first thing in the morning. Make it part of your morning ritual. It is easier than having to remember to take them later in your busy day.


A healthy immune system requires a variety of vitamins and nutrients in order to do its job properly. Vitamins that play a role in immune function include vitamins C, D, and Zinc in addition to others. The food you eat can help you get these vital contributors for immune system health. However, if you are unable to get all the vitamins you need from your everyday diet, you might want to consider taking a daily supplement.

Frunutta line of supplements and products contain vitamins and nutrients to help support the immune system and your health.

The entire line of Frunutta products are simply absorbed under your tongue (sublingually,  bypassing the need to be swallowed or to survive the harsh environment of the gut) or they can be swallowed.

Simply place Frunutta’s instant dissolve soft molded tablets under your tongue and let it absorb directly into your blood stream.

Frunutta vitamins are free from additives, preservatives, colorings, and other impurities.

These statements have not been evaluated by the Food and Drug Administration. Dietary Supplements are not intended to diagnose, treat, cure, or prevent any disease.

This information is only for educational purposes and is not medical advice or intended as a recommendation of any specific products. Consult your health care provider for more information. These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.


  • Zhang Y, Fang F, Tang J, et al. Association between vitamin D supplementation and mortality: systematic review and meta-analysis [published correction appears in BMJ. 2020 Sep 22;370:m2329]. BMJ. 2019;366:l4673. Published 2019 Aug 12. doi:10.1136/bmj.l4673
  • Jayedi A, Rashidy-Pour A, Shab-Bidar S. Vitamin D status and risk of dementia and Alzheimer's disease: A meta-analysis of dose-response . Nutr Neurosci. 2019 Nov;22(11):750-759. doi: 10.1080/1028415X.2018.1436639. Epub 2018 Feb 15. PMID: 29447107.
  • Wimalawansa SJ. Non-musculoskeletal benefits of vitamin D. J Steroid Biochem Mol Biol. 2018 Jan;175:60-81. doi: 10.1016/j.jsbmb.2016.09.016. Epub 2016 Sep 20. PMID: 27662817.
  • Pilz S, Trummer C, Theiler-Schwetz V, Grübler MR, Verheyen ND, Odler B, Karras SN, Zittermann A, März W. Critical Appraisal of Large Vitamin D Randomized Controlled Trials. Nutrients. 2022 Jan 12;14(2):303. doi: 10.3390/nu14020303. PMID: 35057483; PMCID: PMC8778517.
  • Hahn J, Cook NR, Alexander EK, Friedman S, Walter J, Bubes V, Kotler G, Lee IM, Manson JE, Costenbader KH. Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial. BMJ. 2022 Jan 26;376:e066452. doi: 10.1136/bmj-2021-066452. PMID: 35082139; PMCID: PMC8791065.
  • Martineau AR, Jolliffe DA, Hooper RL, Greenberg L, Aloia JF, Bergman P, Dubnov-Raz G, Esposito S, Ganmaa D, Ginde AA, Goodall EC, Grant CC, Griffiths CJ, Janssens W, Laaksi I, Manaseki-Holland S, Mauger D, Murdoch DR, Neale R, Rees JR, Simpson S Jr, Stelmach I, Kumar GT, Urashima M, Camargo CA Jr. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. 2017 Feb 15;356:i6583. doi: 10.1136/bmj.i6583. PMID: 28202713; PMCID: PMC5310969.
  • Manson JE, Cook NR, Lee IM, Christen W, Bassuk SS, Mora S, Gibson H, Gordon D, Copeland T, D'Agostino D, Friedenberg G, Ridge C, Bubes V, Giovannucci EL, Willett WC, Buring JE; VITAL Research Group. Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. N Engl J Med. 2019 Jan 3;380(1):33-44. doi: 10.1056/NEJMoa1809944. Epub 2018 Nov 10. PMID: 30415629; PMCID: PMC6425757.
  • Harvard Health - Can vitamin D supplements prevent autoimmune disease? [Accessed 13 April 2022].
  • Webmd.com - Vitamin D3 Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing - WebMD.  [Accessed 13 April 2022].
  • Vitamin D immune system D3 better [Accessed 13 April 2022].
  •  Bulletproof - The Best Time to Take Vitamin D (and When to Skip It).  [Accessed 13 April 2022].
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