We explored the connection between vitamin D levels and the frequency of upper respiratory tract infections (URTI) in physically active individuals throughout different seasons. In our research, we observed over 1,600 military recruits during their basic training, noting that only 21% were vitamin D sufficient during winter. Alarmingly, those who had sufficient vitamin D levels were found to be 40% less likely to experience URTIs compared to their deficient counterparts, suggesting that maintaining adequate vitamin D may be crucial for better respiratory health during demanding training periods.
Building on these findings, we conducted a follow-up study with 250 recruits, where we implemented various vitamin D supplementation strategies. Participants received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplementation. The results were promising: vitamin D helped alleviate the severity of URTI symptoms and significantly reduced the number of days experiencing a cold. Notably, both sunlight and dietary supplementation were equally effective in boosting vitamin D levels and improving outcomes.
Overall, achieving vitamin D sufficiency can markedly reduce the burden of URTIs, particularly in physically demanding scenarios such as military training.
Read More
8
Vitamin D3 aids cold recovery
Intake of 25-Hydroxyvitamin D3 Reduces Duration and Severity of Upper Respiratory Tract Infection: A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study.
We explored whether taking 25-hydroxyvitamin D3, a form of vitamin D, could have a positive impact on upper respiratory tract infections (URTIs), commonly known as colds. To do this, we conducted a randomized, double-blind, placebo-controlled study at clinics in Japan, involving 428 participants aged between 45 and 74 years.
Participants were divided into two groups: one received a daily dose of 10 micrograms of vitamin D3, while the other group received a placebo for 16 weeks. We monitored the frequency of URTIs, their severity, the participants’ quality of life, and the duration of the infections.
Our findings revealed that those who took vitamin D3 experienced shorter durations of URTIs, less severe symptoms, and better quality of life during their illness compared to those on the placebo. This suggests that vitamin D3 may help mitigate the discomfort associated with colds and potentially make us feel better more quickly when we are sick.
Read More
8
Vitamin D’s role in cold prevention
Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds-Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds.
We examined the role of vitamin D in managing common colds, delving into how it interacts with our immune system to potentially lessen the severity and duration of symptoms. The study highlighted that individuals with vitamin D deficiency, as well as those not receiving large doses, are more likely to benefit from vitamin D supplementation during cold episodes.
Findings suggest that vitamin D might act as a protective agent against common colds overall. Taking vitamin D regularly could help fortify our immune response, which plays a crucial part in fighting off the viruses responsible for colds. The research points towards the idea that maintaining adequate vitamin D levels may offer significant advantages for keeping our immune system vigilant.
However, it’s essential to approach this information with a measure of caution, as further research is necessary to draw definitive conclusions. Overall, encouraging patients to consider vitamin D as a part of their cold prevention strategy seems promising.
Read More
Most Useful Reviews
9
Boosted immunity
529 people found this helpful
After regularly taking vitamin D3, both my child and I have practically stopped suffering from the common cold. My daughter consistently broke kindergarten attendance records and rarely fell ill during the winter months. I've noticed I feel more energetic too. When I stop taking the supplement, my thoracic spine often aches, but it improves as soon as I resume the vitamin D3. I'm very pleased with the results.
Read More
9
Rapid recovery
6 people found this helpful
This is a fantastic product! I’ve recently started using it for my three children. At the first sign of a common cold, I double the dose, and they either avoid illness or recover twice as fast. They enjoy taking it, even the youngest at 4 years old!
Read More
9
Anxiety reduction
3 people found this helpful
After two months, my vitamin D levels improved significantly. Regular sunlight exposure wasn't helping. I took 10000 IU daily, and now I seldom catch a common cold, and my anxiety symptoms have lessened considerably.
We explored the connection between vitamin D levels and the frequency of upper respiratory tract infections (URTI) in physically active individuals throughout different seasons. In our research, we observed over 1,600 military recruits during their basic training, noting that only 21% were vitamin D sufficient during winter. Alarmingly, those who had sufficient vitamin D levels were found to be 40% less likely to experience URTIs compared to their deficient counterparts, suggesting that maintaining adequate vitamin D may be crucial for better respiratory health during demanding training periods.
Building on these findings, we conducted a follow-up study with 250 recruits, where we implemented various vitamin D supplementation strategies. Participants received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplementation. The results were promising: vitamin D helped alleviate the severity of URTI symptoms and significantly reduced the number of days experiencing a cold. Notably, both sunlight and dietary supplementation were equally effective in boosting vitamin D levels and improving outcomes.
Overall, achieving vitamin D sufficiency can markedly reduce the burden of URTIs, particularly in physically demanding scenarios such as military training.
Read More
8
Vitamin D’s role in cold prevention
Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds-Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds.
We examined the role of vitamin D in managing common colds, delving into how it interacts with our immune system to potentially lessen the severity and duration of symptoms. The study highlighted that individuals with vitamin D deficiency, as well as those not receiving large doses, are more likely to benefit from vitamin D supplementation during cold episodes.
Findings suggest that vitamin D might act as a protective agent against common colds overall. Taking vitamin D regularly could help fortify our immune response, which plays a crucial part in fighting off the viruses responsible for colds. The research points towards the idea that maintaining adequate vitamin D levels may offer significant advantages for keeping our immune system vigilant.
However, it’s essential to approach this information with a measure of caution, as further research is necessary to draw definitive conclusions. Overall, encouraging patients to consider vitamin D as a part of their cold prevention strategy seems promising.
Read More
8
Vitamin D3 aids cold recovery
Intake of 25-Hydroxyvitamin D3 Reduces Duration and Severity of Upper Respiratory Tract Infection: A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study.
We explored whether taking 25-hydroxyvitamin D3, a form of vitamin D, could have a positive impact on upper respiratory tract infections (URTIs), commonly known as colds. To do this, we conducted a randomized, double-blind, placebo-controlled study at clinics in Japan, involving 428 participants aged between 45 and 74 years.
Participants were divided into two groups: one received a daily dose of 10 micrograms of vitamin D3, while the other group received a placebo for 16 weeks. We monitored the frequency of URTIs, their severity, the participants’ quality of life, and the duration of the infections.
Our findings revealed that those who took vitamin D3 experienced shorter durations of URTIs, less severe symptoms, and better quality of life during their illness compared to those on the placebo. This suggests that vitamin D3 may help mitigate the discomfort associated with colds and potentially make us feel better more quickly when we are sick.
We observed the important role that vitamin D plays in maintaining a healthy immune system, particularly regarding the common cold. Research indicates that vitamin D may help limit the incidence and duration of infections, which can be especially beneficial for athletes.
Notably, many individuals, including athletes, often exhibit low vitamin D levels, especially during winter months. This deficiency may increase the risk of catching common illnesses like colds and flu.
While studies suggest that vitamin D can have a positive effect on immune function, the evidence around its effectiveness specifically for the common cold isn't overwhelming. We found that a well-balanced approach to nutrition, rather than relying solely on supplements, is essential for optimal immune health in athletes.
Read More
8
Efficacy of micronutrients on colds
[Dietary efficacy of a micronutrient combination in patients with recurrent upper respiratory tract infections. Results of a placebo-controlled double-blind study].
We explored how a combination of vitamins and minerals, including vitamin D, could potentially influence the frequency and severity of common colds among individuals who frequently suffer from upper respiratory infections. In a well-structured study involving 192 participants, we conducted a randomized, placebo-controlled, double-blind trial that lasted for 16 weeks.
Throughout the trial, we monitored a range of factors, including the number and intensity of cold symptoms. Notably, those who received the micronutrient combination, which encompassed vitamins like C and D as well as other essential nutrients, reported significant improvements compared to participants who received a placebo.
Our findings revealed that patients who were initially experiencing a severe common cold saw a notable decrease in their symptoms. Additionally, individuals under 45 years who took the micronutrient blend were less likely to miss work during cold episodes. Importantly, those with initially low levels of vitamin D and C reported fewer colds while taking the supplements.
While vitamin D played a role alongside other micronutrients in improving cold symptoms and reducing infection frequencies, we must recognize that it was part of a broader combination. Thus, while we observed promising results, the specific contribution of vitamin D alone remains challenging to delineate.
After regularly taking vitamin D3, both my child and I have practically stopped suffering from the common cold. My daughter consistently broke kindergarten attendance records and rarely fell ill during the winter months. I've noticed I feel more energetic too. When I stop taking the supplement, my thoracic spine often aches, but it improves as soon as I resume the vitamin D3. I'm very pleased with the results.
Read More
9
Rapid recovery
6 people found this helpful
This is a fantastic product! I’ve recently started using it for my three children. At the first sign of a common cold, I double the dose, and they either avoid illness or recover twice as fast. They enjoy taking it, even the youngest at 4 years old!
Read More
9
Anxiety reduction
3 people found this helpful
After two months, my vitamin D levels improved significantly. Regular sunlight exposure wasn't helping. I took 10000 IU daily, and now I seldom catch a common cold, and my anxiety symptoms have lessened considerably.
Read More
9
Effective vitamin D
1 people found this helpful
My daughter is thrilled! I trust Now Foods for vitamins and these are no exception. I give her 1000 IU as prescribed by the doctor. They taste great and have no allergic side effects. Vitamin D is vital all year round!
Read More
9
Faster recovery
1 people found this helpful
The children happily take one tablet a day. Their ages are 3 and 9, and I’ve found that their common colds pass much more quickly and are milder than before.
The common cold is a viral infection of the upper respiratory tract, primarily affecting the nose and throat. It's caused by a variety of viruses, with rhinoviruses being the most prevalent. Symptoms generally include a runny or stuffy nose, sore throat, cough, sneezing, mild headache, and sometimes a low-grade fever. While the common cold is often mild and resolves on its own within a week or two, it can still be bothersome and impact daily activities.
Transmission occurs through respiratory droplets when an infected person coughs or sneezes, or by touching surfaces contaminated with the virus. Preventative measures include frequent handwashing, using hand sanitizer, and avoiding close contact with infected individuals. Since there is currently no cure for the common cold, treatment focuses on symptom relief through over-the-counter medications, adequate rest, and hydration. While colds may be uncomfortable, they are generally not serious; however, seeking medical attention may be necessary if symptoms worsen or persist for an extended period.
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.
While the role of Vitamin D in immune function is well-established, particularly its potential to enhance innate immunity, the evidence linking Vitamin D supplementation specifically to the prevention or treatment of the common cold is still not conclusive. Some studies suggest that adequate levels of Vitamin D may reduce the incidence of respiratory infections, including colds, particularly in individuals who are deficient in this essential nutrient. For example, individuals with lower Vitamin D levels may have a higher risk of upper respiratory tract infections.
However, other research has not found a distinctive benefit from Vitamin D in preventing or reducing the severity of colds for the general population. It is important to note that while Vitamin D can play a role in bolstering overall immune health, relying solely on it to prevent the common cold is not advisable. A balanced diet, proper hygiene, and other preventive measures remain crucial in managing common colds. If you're considering Vitamin D supplementation, it’s always best to consult with a healthcare professional.
Based on user reviews, the time it typically takes to see results from taking vitamin D3 for common colds varies among individuals, but many users report noticeable benefits within a few weeks to a couple of months. For example, one user noted that their vitamin D levels improved significantly after two months, which corresponded with a reduction in the frequency of colds and anxiety symptoms Read Review. Another review indicated a boosted immune response as soon as the dosage was increased at the initial signs of a cold Read Review.
Some users have experienced quicker recoveries or a decrease in cold severity in just a few days when using the supplement at the first sign of illness Read Review. Overall, the consistently shared sentiment suggests that while users may begin to feel more energetic and notice improvements fairly quickly, the cumulative protective effects against common colds become more apparent within a few weeks to two months of regular use.
Vitamin D supplementation appears to be supported by scientific research for its role in managing symptoms associated with the common cold. Several studies demonstrate that adequate levels of vitamin D can potentially reduce the severity and duration of upper respiratory tract infections (URTIs). For instance, a study involving military recruits found that those with sufficient vitamin D were 40% less likely to experience URTIs, and subsequent supplementation helped decrease the intensity of cold symptoms and shortened the duration of infections [1]. Similarly, research indicates that participants taking vitamin D3 experienced notable reductions in the severity of their cold symptoms, enhanced quality of life during illness, and shorter durations of URTIs compared to a placebo group [4].
However, while the evidence points to the benefits of vitamin D in alleviating cold symptoms, it is important to note that results can be nuanced. For example, some studies highlighted that while vitamin D helped reduce certain symptoms, it did not significantly impact the overall number of cold episodes experienced [2]. Additionally, findings from trials using combinations of micronutrients, including vitamin D, show improvements in cold symptoms, but it remains challenging to isolate the specific effects of vitamin D from other nutrients in these mixtures [6]. Overall, maintaining optimal vitamin D levels may enhance immune responses and help mitigate the burden of common colds, but further focused research would clarify its efficacy and specific contributions.
Based on user reviews, many individuals have reported significant improvements in symptom management with regular use of vitamin D3, particularly concerning common colds and overall wellness. For instance, one parent noted that both they and their child experienced a dramatic decrease in cold occurrences, with their daughter missing fewer days of school due to illness during winter months Read Review. Additionally, parents have shared that upon increasing the dosage at the first sign of a cold, their children either avoided illness altogether or enjoyed notably faster recoveries Read Review.
Moreover, anecdotal evidence suggests that users feel an improvement in energy levels and a reduction in anxiety symptoms after consistent vitamin D3 supplementation. One user mentioned a marked improvement in their vitamin D levels and a notable decrease in both cold incidences and anxiety after about two months of use Read Review. Similarly, several parents reported that their children were getting sick less frequently and that when they did catch a cold, symptoms were milder and recovery was quicker Read Review. While results can vary from individual to individual, the collective feedback reflects a positive trend in symptom management with vitamin D3 use.
Based on user reviews, many individuals find that combining vitamin D3 with other supplements, such as zinc and vitamin C, enhances their effectiveness in managing common colds. For instance, one parent of three reported that their pediatrician recommended taking vitamin D3 alongside zinc and vitamin C, which they believe has improved recovery during cold outbreaks Read Review. Users also commonly mention increasing the dosage of vitamin D3 at the first sign of a cold, leading to quicker recoveries for both children and adults Read Review.
Additionally, many parents echo the sentiment that a higher dose during illness can result in more rapid symptom alleviation, suggesting a beneficial synergy when combined with other health practices or supplements Read Review. The consistent feedback implies that using vitamin D3 not only independently improves immunity but can also enhance the efficacy of other supplements, particularly when addressing common colds in children and adults alike.
According to recent research, an optimal daily dose of 10 micrograms (μg) of vitamin D3 may be effective for treating symptoms of the common cold. In a randomized, double-blind, placebo-controlled study involving 428 participants aged 45 to 74, those who received this dosage experienced shorter durations of upper respiratory tract infections (URTIs) and reported less severe symptoms overall, compared to those on a placebo [4].
Furthermore, additional studies suggest that vitamin D3 can alleviate nasal symptoms such as runny nose and head congestion, thereby improving quality of life during these illnesses [2]. However, it’s vital to note that while vitamin D may help in managing cold symptoms, it does not seem to significantly reduce the frequency of colds themselves [2]. If you're considering adding vitamin D3 to your health regimen during cold season, consulting with a healthcare professional is a good step to determine the best dosage and approach for your individual needs.
9
Anxiety reduction
3 people found this helpful
After two months, my vitamin D levels improved significantly. Regular sunlight exposure wasn't helping. I took 10000 IU daily, and now I seldom catch a common cold, and my anxiety symptoms have lessened considerably.
9
Rapid recovery
6 people found this helpful
This is a fantastic product! I’ve recently started using it for my three children. At the first sign of a common cold, I double the dose, and they either avoid illness or recover twice as fast. They enjoy taking it, even the youngest at 4 years old!
9
Faster recovery
1 people found this helpful
The children happily take one tablet a day. Their ages are 3 and 9, and I’ve found that their common colds pass much more quickly and are milder than before.
9
Boosted immunity
529 people found this helpful
After regularly taking vitamin D3, both my child and I have practically stopped suffering from the common cold. My daughter consistently broke kindergarten attendance records and rarely fell ill during the winter months. I've noticed I feel more energetic too. When I stop taking the supplement, my thoracic spine often aches, but it improves as soon as I resume the vitamin D3. I'm very pleased with the results.
8
Trusted brand
1 people found this helpful
I ordered for my 7-year-old. I’ve trusted this brand for years, and the small size makes it easy. The paediatrician recommended one daily, and combined with zinc and vitamin C, it helps with common colds.
7.5
Reduced colds incidence
2 people found this helpful
Kids enjoy these! I only give them when I have a cold, but I know they’re beneficial. Since using them, my children have been getting sick less often. I recommend them to everyone! Stay healthy!
8
Vitamin D reduces cold severity
Influence of Vitamin D Supplementation by Simulated Sunlight or Oral D3 on Respiratory Infection during Military Training.
We explored the connection between vitamin D levels and the frequency of upper respiratory tract infections (URTI) in physically active individuals throughout different seasons. In our research, we observed over 1,600 military recruits during their basic training, noting that only 21% were vitamin D sufficient during winter. Alarmingly, those who had sufficient vitamin D levels were found to be 40% less likely to experience URTIs compared to their deficient counterparts, suggesting that maintaining adequate vitamin D may be crucial for better respiratory health during demanding training periods.
Building on these findings, we conducted a follow-up study with 250 recruits, where we implemented various vitamin D supplementation strategies. Participants received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplementation. The results were promising: vitamin D helped alleviate the severity of URTI symptoms and significantly reduced the number of days experiencing a cold. Notably, both sunlight and dietary supplementation were equally effective in boosting vitamin D levels and improving outcomes.
Overall, achieving vitamin D sufficiency can markedly reduce the burden of URTIs, particularly in physically demanding scenarios such as military training.
8
Vitamin D3 aids cold recovery
Intake of 25-Hydroxyvitamin D3 Reduces Duration and Severity of Upper Respiratory Tract Infection: A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study.
We explored whether taking 25-hydroxyvitamin D3, a form of vitamin D, could have a positive impact on upper respiratory tract infections (URTIs), commonly known as colds. To do this, we conducted a randomized, double-blind, placebo-controlled study at clinics in Japan, involving 428 participants aged between 45 and 74 years.
Participants were divided into two groups: one received a daily dose of 10 micrograms of vitamin D3, while the other group received a placebo for 16 weeks. We monitored the frequency of URTIs, their severity, the participants’ quality of life, and the duration of the infections.
Our findings revealed that those who took vitamin D3 experienced shorter durations of URTIs, less severe symptoms, and better quality of life during their illness compared to those on the placebo. This suggests that vitamin D3 may help mitigate the discomfort associated with colds and potentially make us feel better more quickly when we are sick.
7
Vitamin D alleviates cold symptoms
Intake of 25-Hydroxyvitamin D May Reduce the Severity of Upper Respiratory Tract Infection: Post hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study.
We explored the potential benefits of 25-hydroxyvitamin D (25OHD) in alleviating symptoms of the common cold, specifically during upper respiratory tract infections (URTIs). In our analysis, we utilized data from a randomized, double-blind, placebo-controlled study where participants received either 10 μg of 25OHD or a placebo for 16 weeks.
Our findings revealed that participants in the vitamin D group reported significantly fewer physical symptoms such as runny nose, sneezing, and head congestion compared to those who received the placebo. Additionally, we observed improvements in quality of life scores, particularly regarding various symptoms.
However, it’s essential to note that there were no significant differences in the overall number of URTI episodes or the use of medications like antibiotics and analgesics between the two groups.
Overall, this study suggests that adequate intake of vitamin D can help ease physical discomfort associated with the onset of common colds, especially nasal symptoms, potentially enhancing our quality of life during such infections.
8
Efficacy of micronutrients on colds
[Dietary efficacy of a micronutrient combination in patients with recurrent upper respiratory tract infections. Results of a placebo-controlled double-blind study].
We explored how a combination of vitamins and minerals, including vitamin D, could potentially influence the frequency and severity of common colds among individuals who frequently suffer from upper respiratory infections. In a well-structured study involving 192 participants, we conducted a randomized, placebo-controlled, double-blind trial that lasted for 16 weeks.
Throughout the trial, we monitored a range of factors, including the number and intensity of cold symptoms. Notably, those who received the micronutrient combination, which encompassed vitamins like C and D as well as other essential nutrients, reported significant improvements compared to participants who received a placebo.
Our findings revealed that patients who were initially experiencing a severe common cold saw a notable decrease in their symptoms. Additionally, individuals under 45 years who took the micronutrient blend were less likely to miss work during cold episodes. Importantly, those with initially low levels of vitamin D and C reported fewer colds while taking the supplements.
While vitamin D played a role alongside other micronutrients in improving cold symptoms and reducing infection frequencies, we must recognize that it was part of a broader combination. Thus, while we observed promising results, the specific contribution of vitamin D alone remains challenging to delineate.
References
Harrison SE, Oliver SJ, Kashi DS, Carswell AT, Edwards JP, et al. Influence of Vitamin D Supplementation by Simulated Sunlight or Oral D3 on Respiratory Infection during Military Training. Med Sci Sports Exerc. 2021;53:1505. doi:10.1249/MSS.0000000000002604
Shimizu Y, Ito Y, Uotsu N, Yui K. Intake of 25-Hydroxyvitamin D May Reduce the Severity of Upper Respiratory Tract Infection: Post hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study. Nutrients. 2020;12. doi:10.3390/nu12123769
Rondanelli M, Miccono A, Lamburghini S, Avanzato I, Riva A, et al. Self-Care for Common Colds: The Pivotal Role of Vitamin D, Vitamin C, Zinc, and in Three Main Immune Interactive Clusters (Physical Barriers, Innate and Adaptive Immunity) Involved during an Episode of Common Colds-Practical Advice on Dosages and on the Time to Take These Nutrients/Botanicals in order to Prevent or Treat Common Colds. Evid Based Complement Alternat Med. 2018;2018:5813095. doi:10.1155/2018/5813095
Shimizu Y, Ito Y, Yui K, Egawa K, Orimo H. Intake of 25-Hydroxyvitamin D3 Reduces Duration and Severity of Upper Respiratory Tract Infection: A Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study. J Nutr Health Aging. 2018;22:491. doi:10.1007/s12603-017-0952-x
Gleeson M. Immunological aspects of sport nutrition. Immunol Cell Biol. 2016;94:117. doi:10.1038/icb.2015.109
Schmidt K, Zirkler S. [Dietary efficacy of a micronutrient combination in patients with recurrent upper respiratory tract infections. Results of a placebo-controlled double-blind study]. MMW Fortschr Med. 2011;153 Suppl 3:83.
Schmidt K, Zirkler S. [Dietary efficacy of a micronutrient combination in patients with recurrent upper respiratory tract infections. Results of a placebo-controlled doubleblind study.]. MMW Fortschr Med. 2011;153:83. doi:10.1007/s15006-011-1630-2