We explored the potential benefits of vitamin D supplementation for reducing the risk of influenza infections. Through a comprehensive analysis of multiple Randomized Controlled Trials (RCTs), we aimed to clarify whether taking vitamin D can help prevent the flu.
Our investigation identified 10 relevant trials that included a total of 4,859 participants. These studies varied in their dosages and duration of vitamin D use, allowing us to assess overall effectiveness across different populations.
The findings were encouraging: our analysis demonstrated that vitamin D supplementation appears to significantly reduce the risk of getting influenza, suggesting that those who increase their vitamin D intake might be better protected during flu season.
Importantly, we did not find significant differences between the studies that could affect our result, and there was no hint of publication bias. Consequently, we can confidently suggest that including vitamin D in our health strategies could enhance our defenses against the flu.
Read More
8
Vitamin D3 reduces flu incidence
Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren.
We carried out a study to investigate whether vitamin D3 supplements could help prevent seasonal influenza A in schoolchildren. Our approach involved a randomized, double-blind, placebo-controlled trial conducted from December 2008 to March 2009.
This ensured that neither the participants nor the researchers knew who was receiving the vitamin D3 or the placebo, making our findings more reliable. During the trial, we provided 1200 IU of vitamin D3 daily to one group while the other received a placebo.
The results were promising; we found that only 10.8% of the children taking vitamin D3 contracted influenza A, compared to 18.6% in the placebo group. This reduced incidence led us to a relative risk of 0.58, suggesting that vitamin D3 supplementation may lower the chances of getting the flu.
Interestingly, we noticed the most significant benefits among children who hadn’t been taking any other vitamin D supplements and those who began nursery school after age three. Additionally, in children with a past asthma diagnosis, vitamin D3 seemed to dramatically reduce asthma attacks.
Overall, our findings indicate that taking vitamin D3 in the winter could be beneficial for schoolchildren, especially for certain groups. We believe this study adds valuable insights into preventive health measures against influenza A.
Read More
8
Vitamin D3 reduces flu-like illnesses
Vitamin D3 Supplementation at 5000 IU Daily for the Prevention of Influenza-like Illness in Healthcare Workers: A Pragmatic Randomized Clinical Trial.
We conducted a practical study to investigate how daily vitamin D3 supplementation at 5000 IU might help reduce flu-like illnesses in healthcare workers. This was especially important during the COVID-19 pandemic, where preventing viral infections is crucial for those on the front lines.
Our study involved 255 healthcare workers who received the vitamin D3 supplement for at least two months and compared them to a control group of 2827 workers who did not receive the supplement. We asked participants to monitor themselves for any flu-like symptoms and report for COVID-19 testing accordingly.
The results were promising; those supplementing with vitamin D experienced a significant reduction in the incidence of flu-like illnesses. The numbers showed a noteworthy drop in non-COVID-19 flu-like illness rates among those taking the supplement. However, when it came to COVID-19 related flu-like illnesses, the difference was not statistically significant.
Overall, our exploration of vitamin D3's effects suggests that it may be a beneficial addition to the health routines of healthcare workers to stave off flu-like illnesses, although its influence on COVID-19 specifically requires further investigation.
Read More
Most Useful Reviews
7.5
Flu-free for years
8 people found this helpful
I am very happy with this brand. While some information downplays Vitamin D's role, I find these studies flawed. I haven't had a severe cold or any flu for over a decade by supplementing with it, especially in winter. A balanced diet is essential, and I take 5000 IU as it is affordable and works for me.
Read More
9
No flu since use
7 people found this helpful
I’m nearly 49, have had asthma all my life, and have never had a flu shot. For several years, I’ve taken this product at 10,000 IU daily, and I haven’t caught the flu or any virus in about three or four years. It also helps with depression as Vitamin D from the sun does.
Read More
7.5
Defence against flu
4 people found this helpful
An important vitamin. A study confirmed that vitamin D supplementation can protect against acute respiratory infections. I’ve taken D3 for decades without a flu shot, only having had the flu once in 1995. I take 4000 IU about five times a week. While it's correlation rather than causation, I strongly believe in its benefits.
We recently examined how vitamin D impacts our body's response to influenza H1N1, an important viral infection. Utilizing 142 clinical cases from the Department of Otolaryngology at Sun Yat-sen University, we dug into the effects of vitamin D deficiency on chronic rhinosinusitis (CRS), a condition that frequently involves damage to the airway's lining. By studying airway organoids treated with vitamin D, we were able to simulate how this treatment might bolster our defenses against flu viruses and bacteria like Staphylococcus aureus.
Our observations showed that many patients with CRS suffered from vitamin D deficiency. Notably, those who received vitamin D treatment exhibited faster cell growth in the nasal epithelium. When exposed to the H1N1 virus, these treated organoids demonstrated a remarkable ability to fend off the infection better than those without vitamin D. This protection stemmed from enhancements in host defenses, including improved production of antimicrobial proteins, reduced inflammation, and better epithelial integrity—crucial factors in fighting off infections.
We also uncovered some fascinating insights about the biological mechanisms at work. Vitamin D seemed to actively influence how epithelial cells develop and repair themselves while managing immune responses against infections. These findings underscore the significance of addressing vitamin D deficiency, especially for those vulnerable to respiratory illnesses.
Read More
9
Oxarol enhances flu vaccine response
Repurposing the psoriasis drug Oxarol to an ointment adjuvant for the influenza vaccine.
We explored the potential of Oxarol, a medication usually prescribed for psoriasis, as a new adjuvant for influenza vaccines. In our research, we found that applying Oxarol ointment on the skin significantly enhanced the immune response of mice when they were vaccinated against the flu. This treatment helped boost humoral responses—essentially the production of antibodies—and improved germinal center reactions, which are critical for effective immunity.
Our findings highlighted that the vitamin D3 receptor in skin cells played a vital role in this process. By stimulating the production of a molecule called thymic stromal lymphopoietin (TSLP), Oxarol effectively facilitated better immune responses against the virus. Experiments showed that giving mice TSLP directly or blocking it produced noticeable changes in their immune responses, indicating its importance.
Importantly, we identified specific immune cells responsible for the effective response, confirming that targeted treatments like Oxarol could pave the way for safer and more efficient vaccine strategies in the future. This study suggests that vitamin D3’s role in skin treatments can be harnessed to improve flu vaccines.
Read More
8
Vitamin D may reduce flu risk
The effectiveness of interventions to reduce the transmission of acute respiratory infections in care homes: a systematic review.
We explored how vitamin D supplementation might help reduce the risk of respiratory infections, particularly the flu, in care homes. Our systematic review of several randomized controlled trials focused on interventions to reduce the transmission of acute respiratory infections, looking beyond just vaccines.
Our findings highlighted that high-dose vitamin D supplementation led to a significant decrease in the incidence of acute respiratory infections, reducing the likelihood of getting sick. Specifically, one trial indicated a 40% reduction in these infections among participants receiving vitamin D compared to those who did not.
However, not all studies we reviewed showed compelling results for related supplements like vitamins, minerals, probiotics, and herbal aids, which did not significantly impact infection rates. This means that while vitamin D supplementation shows promise, more research is needed to fully understand its effects and confirm its benefits in combating flu and other respiratory illnesses.
Read More
8
Vitamin D3 reduces flu-like illnesses
Vitamin D3 Supplementation at 5000 IU Daily for the Prevention of Influenza-like Illness in Healthcare Workers: A Pragmatic Randomized Clinical Trial.
We conducted a practical study to investigate how daily vitamin D3 supplementation at 5000 IU might help reduce flu-like illnesses in healthcare workers. This was especially important during the COVID-19 pandemic, where preventing viral infections is crucial for those on the front lines.
Our study involved 255 healthcare workers who received the vitamin D3 supplement for at least two months and compared them to a control group of 2827 workers who did not receive the supplement. We asked participants to monitor themselves for any flu-like symptoms and report for COVID-19 testing accordingly.
The results were promising; those supplementing with vitamin D experienced a significant reduction in the incidence of flu-like illnesses. The numbers showed a noteworthy drop in non-COVID-19 flu-like illness rates among those taking the supplement. However, when it came to COVID-19 related flu-like illnesses, the difference was not statistically significant.
Overall, our exploration of vitamin D3's effects suggests that it may be a beneficial addition to the health routines of healthcare workers to stave off flu-like illnesses, although its influence on COVID-19 specifically requires further investigation.
Read More
8
Vitamin D reduces flu risk
Association Between Vitamin D and Influenza: Meta-Analysis and Systematic Review of Randomized Controlled Trials.
We explored the potential benefits of vitamin D supplementation for reducing the risk of influenza infections. Through a comprehensive analysis of multiple Randomized Controlled Trials (RCTs), we aimed to clarify whether taking vitamin D can help prevent the flu.
Our investigation identified 10 relevant trials that included a total of 4,859 participants. These studies varied in their dosages and duration of vitamin D use, allowing us to assess overall effectiveness across different populations.
The findings were encouraging: our analysis demonstrated that vitamin D supplementation appears to significantly reduce the risk of getting influenza, suggesting that those who increase their vitamin D intake might be better protected during flu season.
Importantly, we did not find significant differences between the studies that could affect our result, and there was no hint of publication bias. Consequently, we can confidently suggest that including vitamin D in our health strategies could enhance our defenses against the flu.
I am very happy with this brand. While some information downplays Vitamin D's role, I find these studies flawed. I haven't had a severe cold or any flu for over a decade by supplementing with it, especially in winter. A balanced diet is essential, and I take 5000 IU as it is affordable and works for me.
Read More
9
No flu since use
7 people found this helpful
I’m nearly 49, have had asthma all my life, and have never had a flu shot. For several years, I’ve taken this product at 10,000 IU daily, and I haven’t caught the flu or any virus in about three or four years. It also helps with depression as Vitamin D from the sun does.
Read More
7.5
Defence against flu
4 people found this helpful
An important vitamin. A study confirmed that vitamin D supplementation can protect against acute respiratory infections. I’ve taken D3 for decades without a flu shot, only having had the flu once in 1995. I take 4000 IU about five times a week. While it's correlation rather than causation, I strongly believe in its benefits.
Read More
Frequently Asked Questions
The flu, short for influenza, is a contagious respiratory illness caused by influenza viruses. It affects the nose, throat, and sometimes the lungs, leading to a range of symptoms that can vary in severity. Common symptoms include fever, chills, muscle aches, cough, congestion, runny nose, headaches, and fatigue. The flu can lead to serious complications, particularly in vulnerable populations such as young children, the elderly, pregnant women, and those with underlying health conditions.
The flu virus spreads primarily through respiratory droplets when an infected person coughs, sneezes, or talks. It can also be transmitted by touching surfaces contaminated with the virus and then touching one's face. Vaccination is the most effective way to prevent the flu, and the vaccine is typically updated annually to provide protection against the most common circulating strains. In addition to vaccination, practicing good hygiene, such as frequent handwashing and respiratory etiquette, can help minimize the risk of infection.
Vitamin D is a fat-soluble vitamin that's essential for maintaining healthy bones and teeth, supporting immune system function, and facilitating normal cell growth and development. It plays a crucial role in calcium absorption in the gut, which is vital for bone health. Unlike most vitamins, our bodies can produce Vitamin D when exposed to sunlight, specifically UVB rays, which is why it’s often referred to as the "sunshine vitamin." However, depending on your geographical location, lifestyle, and skin type, getting sufficient Vitamin D from the sun alone can be challenging, particularly during the winter months.
In addition to sunlight, Vitamin D can be obtained from certain foods such as fatty fish (like salmon and mackerel), fish liver oils, and fortified foods like milk and cereals. Some individuals may also consider supplements, especially if they're at risk for deficiency. Insufficient vitamin D levels are linked to various health issues, including rickets in children, osteomalacia in adults, and even an increased risk of chronic diseases. Regularly checking your vitamin D levels and consulting with a healthcare professional can help ensure you're meeting your needs for optimal health.
Vitamin D has been shown to play a crucial role in immune function, and there is some evidence suggesting that it may help reduce the risk of respiratory infections, including the flu. Some studies indicate that individuals with adequate levels of Vitamin D might experience fewer infections and potentially milder symptoms if they do contract the flu. This correlation is thought to be due to Vitamin D's ability to modulate the immune system and promote the production of antimicrobial proteins in the respiratory tract.
However, while a deficiency in Vitamin D is linked to an increased susceptibility to infections, it's important to note that taking Vitamin D supplements should not be seen as a substitute for traditional flu prevention measures, such as vaccination and good hygiene practices. Overall, maintaining appropriate Vitamin D levels through a combination of sun exposure, diet, and supplements may contribute to better overall health and potentially help fend off illnesses like the flu, but more research is needed to establish a definitive causal relationship.
Vitamin D supplementation has garnered attention in recent research for its potential role in combating influenza and respiratory infections. Studies indicate that high-dose vitamin D can lead to a significant reduction in the incidence of acute respiratory infections, with one trial showing a remarkable 40% decrease among those receiving vitamin D compared to a control group [1]. Other research has pointed out that vitamin D may strengthen the body's defenses against specific influenza strains, enhancing recovery and reducing inflammation [2]. Overall, the evidence suggests that maintaining adequate vitamin D levels could provide some protective effects against the flu.
However, it is essential to note that not all studies report unequivocal benefits. Some trials with different age demographics, such as the elderly, showed mixed results, with no significant statistical impact on flu infection rates despite supplementation [7]. While vitamin D appears promising in reducing flu-like symptoms among healthcare workers [3], its role in prevention may vary based on individual health conditions and environments. Therefore, while vitamin D supplementation shows potential benefits in flu prevention, further research is vital to establish definitive guidelines and understand the full scope of its effects [6].
The optimal dose of Vitamin D for treating flu isn't straightforward due to varying results from research, but some studies suggest high doses may yield significant benefits. For instance, one investigation indicated that a daily supplementation of 5000 IU of Vitamin D3 resulted in a notable reduction in flu-like illnesses among healthcare workers, highlighting its potential role in enhancing respiratory health and bolstering immune responses against viral infections [3]. Additionally, another study suggested that even a dose of 2000 IU daily showed promising effects in reducing the incidence of influenza A in children [14].
Despite these findings, it's essential to note that there's no universal agreement on the optimal dose, as results can vary widely based on individual health conditions, baseline Vitamin D levels, and specific population groups. While some studies indicate that doses as low as 2000 IU may be beneficial, higher doses like 5000 IU may be required for more significant protective effects [2]. Thus, individuals considering Vitamin D supplementation for flu prevention or treatment should consult healthcare professionals to determine the most appropriate dosage tailored to their specific needs.
8
Vitamin D may reduce flu risk
The effectiveness of interventions to reduce the transmission of acute respiratory infections in care homes: a systematic review.
We explored how vitamin D supplementation might help reduce the risk of respiratory infections, particularly the flu, in care homes. Our systematic review of several randomized controlled trials focused on interventions to reduce the transmission of acute respiratory infections, looking beyond just vaccines.
Our findings highlighted that high-dose vitamin D supplementation led to a significant decrease in the incidence of acute respiratory infections, reducing the likelihood of getting sick. Specifically, one trial indicated a 40% reduction in these infections among participants receiving vitamin D compared to those who did not.
However, not all studies we reviewed showed compelling results for related supplements like vitamins, minerals, probiotics, and herbal aids, which did not significantly impact infection rates. This means that while vitamin D supplementation shows promise, more research is needed to fully understand its effects and confirm its benefits in combating flu and other respiratory illnesses.
9
Vitamin D enhances influenza defenses
Vitamin D promotes epithelial tissue repair and host defense responses against influenza H1N1 virus and Staphylococcus aureus infections.
We recently examined how vitamin D impacts our body's response to influenza H1N1, an important viral infection. Utilizing 142 clinical cases from the Department of Otolaryngology at Sun Yat-sen University, we dug into the effects of vitamin D deficiency on chronic rhinosinusitis (CRS), a condition that frequently involves damage to the airway's lining. By studying airway organoids treated with vitamin D, we were able to simulate how this treatment might bolster our defenses against flu viruses and bacteria like Staphylococcus aureus.
Our observations showed that many patients with CRS suffered from vitamin D deficiency. Notably, those who received vitamin D treatment exhibited faster cell growth in the nasal epithelium. When exposed to the H1N1 virus, these treated organoids demonstrated a remarkable ability to fend off the infection better than those without vitamin D. This protection stemmed from enhancements in host defenses, including improved production of antimicrobial proteins, reduced inflammation, and better epithelial integrity—crucial factors in fighting off infections.
We also uncovered some fascinating insights about the biological mechanisms at work. Vitamin D seemed to actively influence how epithelial cells develop and repair themselves while managing immune responses against infections. These findings underscore the significance of addressing vitamin D deficiency, especially for those vulnerable to respiratory illnesses.
3
Vitamin D fails to prevent flu
The effect of standard-dose wintertime vitamin D supplementation on influenza infection in immunized nursing home elderly residents.
We set out to explore whether a three-month regimen of vitamin D supplementation could lower the risk of influenza infection in elderly nursing home residents who had already received the seasonal flu vaccine. In our study, 97 participants were enrolled, with more than 73% being women. They were divided into two groups: one received vitamin D supplements, while the other did not.
Even though we found that fewer participants in the vitamin D group tested positive for the flu compared to the control group (five versus twelve), the difference was not statistically significant. Most importantly, despite taking the recommended 800 IU of vitamin D each day, residents did not reach sufficient vitamin D levels, and the supplementation did not appear to have any beneficial effect on preventing influenza infections among those already vaccinated.
This highlights a critical aspect: despite being one of the recommended strategies for health improvement, standard vitamin D supplementation may not be effective in significantly reducing the risk of flu in this vulnerable population.
8
Vitamin D3 reduces flu-like illnesses
Vitamin D3 Supplementation at 5000 IU Daily for the Prevention of Influenza-like Illness in Healthcare Workers: A Pragmatic Randomized Clinical Trial.
We conducted a practical study to investigate how daily vitamin D3 supplementation at 5000 IU might help reduce flu-like illnesses in healthcare workers. This was especially important during the COVID-19 pandemic, where preventing viral infections is crucial for those on the front lines.
Our study involved 255 healthcare workers who received the vitamin D3 supplement for at least two months and compared them to a control group of 2827 workers who did not receive the supplement. We asked participants to monitor themselves for any flu-like symptoms and report for COVID-19 testing accordingly.
The results were promising; those supplementing with vitamin D experienced a significant reduction in the incidence of flu-like illnesses. The numbers showed a noteworthy drop in non-COVID-19 flu-like illness rates among those taking the supplement. However, when it came to COVID-19 related flu-like illnesses, the difference was not statistically significant.
Overall, our exploration of vitamin D3's effects suggests that it may be a beneficial addition to the health routines of healthcare workers to stave off flu-like illnesses, although its influence on COVID-19 specifically requires further investigation.
8
Vitamin D reduces flu risk
Association Between Vitamin D and Influenza: Meta-Analysis and Systematic Review of Randomized Controlled Trials.
We explored the potential benefits of vitamin D supplementation for reducing the risk of influenza infections. Through a comprehensive analysis of multiple Randomized Controlled Trials (RCTs), we aimed to clarify whether taking vitamin D can help prevent the flu.
Our investigation identified 10 relevant trials that included a total of 4,859 participants. These studies varied in their dosages and duration of vitamin D use, allowing us to assess overall effectiveness across different populations.
The findings were encouraging: our analysis demonstrated that vitamin D supplementation appears to significantly reduce the risk of getting influenza, suggesting that those who increase their vitamin D intake might be better protected during flu season.
Importantly, we did not find significant differences between the studies that could affect our result, and there was no hint of publication bias. Consequently, we can confidently suggest that including vitamin D in our health strategies could enhance our defenses against the flu.
8
Vitamin D3 reduces flu incidence
Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren.
We carried out a study to investigate whether vitamin D3 supplements could help prevent seasonal influenza A in schoolchildren. Our approach involved a randomized, double-blind, placebo-controlled trial conducted from December 2008 to March 2009.
This ensured that neither the participants nor the researchers knew who was receiving the vitamin D3 or the placebo, making our findings more reliable. During the trial, we provided 1200 IU of vitamin D3 daily to one group while the other received a placebo.
The results were promising; we found that only 10.8% of the children taking vitamin D3 contracted influenza A, compared to 18.6% in the placebo group. This reduced incidence led us to a relative risk of 0.58, suggesting that vitamin D3 supplementation may lower the chances of getting the flu.
Interestingly, we noticed the most significant benefits among children who hadn’t been taking any other vitamin D supplements and those who began nursery school after age three. Additionally, in children with a past asthma diagnosis, vitamin D3 seemed to dramatically reduce asthma attacks.
Overall, our findings indicate that taking vitamin D3 in the winter could be beneficial for schoolchildren, especially for certain groups. We believe this study adds valuable insights into preventive health measures against influenza A.
References
Willcox ML, Lavu D, Yousaf U, Dalton S, Roberts N, et al. The effectiveness of interventions to reduce the transmission of acute respiratory infections in care homes: a systematic review. J Public Health (Oxf). 2024;46:551. 10.1093/pubmed/fdae178
Liao S, Huang Y, Zhang J, Xiong Q, Chi M, et al. Vitamin D promotes epithelial tissue repair and host defense responses against influenza H1N1 virus and Staphylococcus aureus infections. Respir Res. 2023;24:175. 10.1186/s12931-023-02477-4
van Helmond N, Brobyn TL, LaRiccia PJ, Cafaro T, Hunter K, et al. Vitamin D3 Supplementation at 5000 IU Daily for the Prevention of Influenza-like Illness in Healthcare Workers: A Pragmatic Randomized Clinical Trial. Nutrients. 2022;15. 10.3390/nu15010180
Arora J, Patel DR, Nicol MJ, Field CJ, Restori KH, et al. Vitamin D and the Ability to Produce 1,25(OH)D Are Critical for Protection from Viral Infection of the Lungs. Nutrients. 2022;14. 10.3390/nu14153061
Huang YN, Chi H, Chiu NC, Huang CY, Li ST, et al. A randomized trial of vitamin D supplementation to prevent seasonal influenza and enterovirus infection in children. J Microbiol Immunol Infect. 2022;55:803. 10.1016/j.jmii.2022.01.003
Zhu Z, Zhu X, Gu L, Zhan Y, Chen L, et al. Association Between Vitamin D and Influenza: Meta-Analysis and Systematic Review of Randomized Controlled Trials. Front Nutr. 2021;8:799709. 10.3389/fnut.2021.799709
Godan Hauptman A, Lukić-Grlić A, Vraneš J, Milošević M, Gagro A. The effect of standard-dose wintertime vitamin D supplementation on influenza infection in immunized nursing home elderly residents. Croat Med J. 2021;62:495.
Abioye AI, Bromage S, Fawzi W. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis. BMJ Glob Health. 2021;6. 10.1136/bmjgh-2020-003176
Slusky DJG, Zeckhauser RJ. Sunlight and Protection Against Influenza. Econ Hum Biol. 2021;40:100942. 10.1016/j.ehb.2020.100942
Godbole NM, Sinha RA, Tiwari S, Pawar SD, Dhole TN. Analysis of influenza virus-induced perturbation in autophagic flux and its modulation during Vitamin D3 mediated anti-apoptotic signaling. Virus Res. 2020;282:197936. 10.1016/j.virusres.2020.197936
Sato R, Makino-Okamura C, Lin Q, Wang M, Shoemaker JE, et al. Repurposing the psoriasis drug Oxarol to an ointment adjuvant for the influenza vaccine. Int Immunol. 2020;32:499. 10.1093/intimm/dxaa012
Urashima M, Mezawa H, Noya M, Camargo CA. Effects of vitamin D supplements on influenza A illness during the 2009 H1N1 pandemic: a randomized controlled trial. Food Funct. 2014;5:2365. 10.1039/c4fo00371c
Khare D, Godbole NM, Pawar SD, Mohan V, Pandey G, et al. Calcitriol [1, 25[OH]2 D3] pre- and post-treatment suppresses inflammatory response to influenza A (H1N1) infection in human lung A549 epithelial cells. Eur J Nutr. 2013;52:1405. 10.1007/s00394-012-0449-7
Urashima M, Segawa T, Okazaki M, Kurihara M, Wada Y, et al. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr. 2010;91:1255. 10.3945/ajcn.2009.29094
Kriesel JD, Spruance J. Calcitriol (1,25-dihydroxy-vitamin D3) coadministered with influenza vaccine does not enhance humoral immunity in human volunteers. Vaccine. 1999;17:1883.