5/4/2025
Last update
5/4/2025
Reviewed By
Overview
SCIENTIFIC SCORE
Questionable
Based on 8 Researches
6.5
USERS' SCORE
Good
Based on 5 Reviews
8.3
Supplement Facts
Serving Size: 2 Tablets
Amount Per Serving
%DV
Vitamin D3 (as Cholecalciferol)
13 mcg (500 IU)
63%
Calcium (as Calcium Citrate)
630 mg
48%
Top Medical Research Studies
8
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.
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
We investigated how Vitamin D3 might influence the effects of influenza A virus (IAV) on human cells, particularly focusing on its ability to reduce apoptosis, which is the programmed cell death that contributes to tissue damage during flu infections.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
Read More
7
We conducted a thorough investigation to determine whether daily vitamin D3 supplementation, specifically at a dosage of 5000 IU, could lessen the occurrence of flu-like illnesses among healthcare workers. Our study involved a well-structured trial at a tertiary university hospital, where a group of healthcare workers received vitamin D3 supplements over nine months, while another group acted as controls without supplementation.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
Read More
Most Useful Reviews
7.5
Joint improvement noted
3 people found this helpful
Good calcium at a great price. This is not the first time I've taken it for myself and my parents. They noticed the positive effect on their joints and health overall. Calcium is essential for those recovering from fractures, as coffee flushes out calcium from the body. The only drawback is the large size of the tablets, which aren’t easy for everyone to swallow.
Read More
9
Brittle nails improved
1 people found this helpful
Best Calcium! I've had soft nails and thin hair since childhood due to poor calcium absorption. I consume a lot of coffee, which flushes calcium from my body, and I love dairy but can't always eat enough. I sought high-quality calcium tablets and chose this citrate form, which absorbs perfectly. I take one tablet each morning and evening; they are large but manageable. My whole family takes them, and I recommend them!
Read More
9
Pain relief experienced
Excellent quality calcium, bought for my mum, who often has knee and joint pain. Calcium is flushed out quickly from the body as we age, so preventing deficiency is crucial. The tablets have no taste and are sizeable but manageable. After taking them, she forgets about her bone pain. I highly recommend this supplement—it's definitely beneficial.
Read More
Medical Researches
SCIENTIFIC SCORE
Questionable
Based on 8 Researches
6.5
- All Researches
9
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.
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
We investigated how Vitamin D3 might influence the effects of influenza A virus (IAV) on human cells, particularly focusing on its ability to reduce apoptosis, which is the programmed cell death that contributes to tissue damage during flu infections.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
Read More
8
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.
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
7
We explored how vitamin D3 supplementation can influence the transmission of flu in care home residents. Our review involved a systematic analysis of randomized controlled trials, focusing on interventions aimed at preventing acute respiratory infections, excluding vaccines.
Among the various interventions reviewed, we observed that high-dose vitamin D3 supplementation led to a notable reduction in the incidence of respiratory infections. Specifically, one trial showed that participants taking vitamin D3 experienced a 40% lower rate of infections, suggesting that this simple supplement could potentially bolster defenses against the flu.
Importantly, while we found that vitamin D3 can be beneficial, other trials involving different vitamins, minerals, or supplements did not demonstrate significant effects. Thus, while vitamin D3 appears promising, further research is essential to confirm its effectiveness and fully understand its role in protecting against respiratory illnesses like the flu.
Among the various interventions reviewed, we observed that high-dose vitamin D3 supplementation led to a notable reduction in the incidence of respiratory infections. Specifically, one trial showed that participants taking vitamin D3 experienced a 40% lower rate of infections, suggesting that this simple supplement could potentially bolster defenses against the flu.
Importantly, while we found that vitamin D3 can be beneficial, other trials involving different vitamins, minerals, or supplements did not demonstrate significant effects. Thus, while vitamin D3 appears promising, further research is essential to confirm its effectiveness and fully understand its role in protecting against respiratory illnesses like the flu.
Read More
7
We conducted a thorough investigation to determine whether daily vitamin D3 supplementation, specifically at a dosage of 5000 IU, could lessen the occurrence of flu-like illnesses among healthcare workers. Our study involved a well-structured trial at a tertiary university hospital, where a group of healthcare workers received vitamin D3 supplements over nine months, while another group acted as controls without supplementation.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
Read More
User Reviews
USERS' SCORE
Good
Based on 5 Reviews
8.3
- All Reviews
- Positive Reviews
- Negative Reviews
7.5
Joint improvement noted
3 people found this helpful
Good calcium at a great price. This is not the first time I've taken it for myself and my parents. They noticed the positive effect on their joints and health overall. Calcium is essential for those recovering from fractures, as coffee flushes out calcium from the body. The only drawback is the large size of the tablets, which aren’t easy for everyone to swallow.
Read More
9
Brittle nails improved
1 people found this helpful
Best Calcium! I've had soft nails and thin hair since childhood due to poor calcium absorption. I consume a lot of coffee, which flushes calcium from my body, and I love dairy but can't always eat enough. I sought high-quality calcium tablets and chose this citrate form, which absorbs perfectly. I take one tablet each morning and evening; they are large but manageable. My whole family takes them, and I recommend them!
Read More
9
Pain relief experienced
Excellent quality calcium, bought for my mum, who often has knee and joint pain. Calcium is flushed out quickly from the body as we age, so preventing deficiency is crucial. The tablets have no taste and are sizeable but manageable. After taking them, she forgets about her bone pain. I highly recommend this supplement—it's definitely beneficial.
Read More
6
Dental health improved
Calcium citrate was taken as prescribed by the doctor, and I appreciated the inclusion of vitamin D3. A month later, I noticed significant improvement—my teeth felt better and my nails were denser.
Read More
7.5
Joint crunch reduced
Great calcium citrate is the most bioavailable form, and it's a crucial microelement found in bones and the circulatory system. The tablets are quite large but can be divided if needed. After taking them for three months, the crunch in my joints decreased, and I can easily do squats. I plan to do another course; the quality is excellent and the price is appealing.
Read More
Frequently Asked Questions
9
Pain relief experienced
Excellent quality calcium, bought for my mum, who often has knee and joint pain. Calcium is flushed out quickly from the body as we age, so preventing deficiency is crucial. The tablets have no taste and are sizeable but manageable. After taking them, she forgets about her bone pain. I highly recommend this supplement—it's definitely beneficial.
7.5
Joint crunch reduced
Great calcium citrate is the most bioavailable form, and it's a crucial microelement found in bones and the circulatory system. The tablets are quite large but can be divided if needed. After taking them for three months, the crunch in my joints decreased, and I can easily do squats. I plan to do another course; the quality is excellent and the price is appealing.
6
Dental health improved
Calcium citrate was taken as prescribed by the doctor, and I appreciated the inclusion of vitamin D3. A month later, I noticed significant improvement—my teeth felt better and my nails were denser.
7.5
Joint improvement noted
3 people found this helpful
Good calcium at a great price. This is not the first time I've taken it for myself and my parents. They noticed the positive effect on their joints and health overall. Calcium is essential for those recovering from fractures, as coffee flushes out calcium from the body. The only drawback is the large size of the tablets, which aren’t easy for everyone to swallow.
7
We explored how vitamin D3 supplementation can influence the transmission of flu in care home residents. Our review involved a systematic analysis of randomized controlled trials, focusing on interventions aimed at preventing acute respiratory infections, excluding vaccines.
Among the various interventions reviewed, we observed that high-dose vitamin D3 supplementation led to a notable reduction in the incidence of respiratory infections. Specifically, one trial showed that participants taking vitamin D3 experienced a 40% lower rate of infections, suggesting that this simple supplement could potentially bolster defenses against the flu.
Importantly, while we found that vitamin D3 can be beneficial, other trials involving different vitamins, minerals, or supplements did not demonstrate significant effects. Thus, while vitamin D3 appears promising, further research is essential to confirm its effectiveness and fully understand its role in protecting against respiratory illnesses like the flu.
Among the various interventions reviewed, we observed that high-dose vitamin D3 supplementation led to a notable reduction in the incidence of respiratory infections. Specifically, one trial showed that participants taking vitamin D3 experienced a 40% lower rate of infections, suggesting that this simple supplement could potentially bolster defenses against the flu.
Importantly, while we found that vitamin D3 can be beneficial, other trials involving different vitamins, minerals, or supplements did not demonstrate significant effects. Thus, while vitamin D3 appears promising, further research is essential to confirm its effectiveness and fully understand its role in protecting against respiratory illnesses like the flu.
7
We conducted a thorough investigation to determine whether daily vitamin D3 supplementation, specifically at a dosage of 5000 IU, could lessen the occurrence of flu-like illnesses among healthcare workers. Our study involved a well-structured trial at a tertiary university hospital, where a group of healthcare workers received vitamin D3 supplements over nine months, while another group acted as controls without supplementation.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
The results were quite promising. Among the 255 healthcare workers who completed at least two months of the vitamin D3 regimen, we discovered that their risk of experiencing flu-like illnesses was significantly lower compared to the control group. In fact, there was a noteworthy reduction in the rate of non-COVID-19 influenza-like illnesses, which reflects the positive impact of vitamin D3 on respiratory health.
However, when it came to COVID-related flu-like illnesses, the difference wasn’t statistically significant. This suggests that while vitamin D3 is beneficial for reducing general flu-like symptoms, it may not specifically target COVID-19 symptoms as effectively. Overall, our findings indicate that vitamin D3 supplementation can be a valuable tool for healthcare workers in minimizing illness, thereby enhancing their overall well-being and ability to care for patients.
8
We investigated how Vitamin D3 might influence the effects of influenza A virus (IAV) on human cells, particularly focusing on its ability to reduce apoptosis, which is the programmed cell death that contributes to tissue damage during flu infections.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
In our exploration, we used a specific type of human lung cell called A549 to observe the effects of a pandemic strain of IAV. We found that IAV infection led to cell death by disrupting normal autophagy, which is the process cells use to clean up damaged parts and support their survival.
Thankfully, Vitamin D3 appeared to counteract this effect. It helped restore autophagic activity by boosting the expression of certain proteins that are essential for this process. This action led to decreased cell death, suggesting that Vitamin D3 can help protect lung cells during flu infections.
Overall, our findings indicate that Vitamin D3 is a promising candidate for limiting cellular damage during IAV infection through its unique pro-autophagic properties.
7
We examined how vitamin D3, known as calcitriol, influences the body's response to the influenza A virus, particularly in lung epithelial cells. Influenza viruses can trigger respiratory issues, and our immune system manages this through the release of various signaling molecules. While a balanced inflammatory response helps combat infections, an overactive response can worsen symptoms.
Our study focused specifically on how calcitriol treatment, both before and after exposure to the virus, affected the inflammatory responses in human lung A549 cells. We found that although calcitriol didn’t eliminate the virus, it did modify the inflammatory reactions triggered by the infection.
Therefore, our findings suggest that vitamin D supplementation could be beneficial, especially in populations with vitamin D deficiency, by potentially easing the severity of influenza-related inflammation. This opens the door to considering vitamin D as a supportive measure against flu infections.
Our study focused specifically on how calcitriol treatment, both before and after exposure to the virus, affected the inflammatory responses in human lung A549 cells. We found that although calcitriol didn’t eliminate the virus, it did modify the inflammatory reactions triggered by the infection.
Therefore, our findings suggest that vitamin D supplementation could be beneficial, especially in populations with vitamin D deficiency, by potentially easing the severity of influenza-related inflammation. This opens the door to considering vitamin D as a supportive measure against flu infections.
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
- 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
- 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.
