We explored the connection between vitamin D levels and upper respiratory tract infections (URTIs) among military recruits during their training. This observation spanned across different seasons and included over 1,600 recruits. Our aim was to understand how achieving sufficient vitamin D levels could potentially impact the frequency and severity of colds among physically active individuals.
In an additional phase of the research, we conducted a randomized controlled trial with 250 male recruits. They received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplements during winter. This comparison allowed us to see if these methods effectively increased vitamin D levels to a sufficient status of 25(OH)D at 50 nmol/L or higher.
Notably, our findings showed that only 21% of recruits had adequate vitamin D during winter, yet those who did were 40% less likely to suffer from URTIs. Furthermore, both vitamin D supplementation strategies similarly helped nearly all participants achieve sufficient levels. Vitamin D supplementation notably reduced the severity of URTI symptoms by 15% and the number of days with URTIs by 36% compared to placebo.
While the supplementation strategies did not significantly alter other immune factors, such as salivary secretory immunoglobulin A, the overall reduction in respiratory infections indicates a beneficial effect of maintaining vitamin D sufficiency during 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 how 25-hydroxyvitamin D3 (25OHD), a form of vitamin D, influences upper respiratory tract infections (URTIs), commonly known as colds. In a carefully designed clinical study, we followed 428 participants aged 45 to 74 over a 16-week period. They were randomly assigned to receive either 10 μg of 25OHD daily or a placebo, all while maintaining a double-blind setup to ensure accurate results.
Our findings revealed that those who took 25OHD had reduced duration and severity of their cold symptoms. Participants reported improvements in their overall quality of life during the bouts of URTI. By tracking the health of the participants through surveys designed to measure cold symptoms, we gathered valuable data that indicates vitamin D3 could play a helpful role in managing colds.
This suggests that incorporating vitamin D3 into our diets may be beneficial when we catch a cold, potentially leading to a quicker recovery. It’s a promising avenue for anyone looking to ease the discomfort and duration of these frustrating infections.
Read More
7
Vitamin D's limited cold impact
High-dose oral vitamin D supplementation for prevention of infections in children aged 0 to 59 months: a systematic review and meta-analysis.
We evaluated the impact of high-dose vitamin D supplementation, specifically doses exceeding the standard 400 IU, on preventing colds and other infections in children under five years of age. Our analysis included seven studies, involving a total of 5,748 children, which looked into how effective vitamin D might be in reducing the incidence of upper respiratory tract infections.
Interestingly, while our findings showed no significant benefit of high-dose vitamin D on the prevention of upper respiratory tract infections as a whole, we did observe a noteworthy reduction in specific illness occurrences. We noted a 57% reduction in colds, a 56% reduction in coughs, and a 59% decrease in fever rates with daily doses exceeding 1,000 IU.
However, we must approach these findings with caution, as the evidence supporting the reduction in cough and fever was of lower certainty. No significant effects were observed regarding other conditions such as bronchitis or otitis media. Overall, while high-dose vitamin D may help with colds specifically, further research is needed to solidify these conclusions.
Read More
Most Useful Reviews
7.5
Cold prevention
3 people found this helpful
For temporary cold prevention, I take a single dose with vitamin K2 when someone near me has a cold. It appears to be effective. I ensure a week's gap between doses due to potential overdose risks, as noted on the manufacturer's site.
Read More
9
Boosts immunity
1 people found this helpful
I’ve been taking vitamin D3 for several months and the results have been remarkable. It has become essential to my daily routine, elevating my energy and mood significantly. My bones feel stronger and my joints are more mobile. During periods of virus activity, I feel more shielded, avoiding colds. This easy-to-take capsule provides a dose of sunshine that enhances my health daily.
Read More
9
Stops cold onset
1 people found this helpful
I mistakenly bought the wrong size, but when my family started feeling unwell, I took it. Thanks to this, I can prevent colds at their onset, making me very content.
We explored the connection between vitamin D levels and upper respiratory tract infections (URTIs) among military recruits during their training. This observation spanned across different seasons and included over 1,600 recruits. Our aim was to understand how achieving sufficient vitamin D levels could potentially impact the frequency and severity of colds among physically active individuals.
In an additional phase of the research, we conducted a randomized controlled trial with 250 male recruits. They received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplements during winter. This comparison allowed us to see if these methods effectively increased vitamin D levels to a sufficient status of 25(OH)D at 50 nmol/L or higher.
Notably, our findings showed that only 21% of recruits had adequate vitamin D during winter, yet those who did were 40% less likely to suffer from URTIs. Furthermore, both vitamin D supplementation strategies similarly helped nearly all participants achieve sufficient levels. Vitamin D supplementation notably reduced the severity of URTI symptoms by 15% and the number of days with URTIs by 36% compared to placebo.
While the supplementation strategies did not significantly alter other immune factors, such as salivary secretory immunoglobulin A, the overall reduction in respiratory infections indicates a beneficial effect of maintaining vitamin D sufficiency during 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 how 25-hydroxyvitamin D3 (25OHD), a form of vitamin D, influences upper respiratory tract infections (URTIs), commonly known as colds. In a carefully designed clinical study, we followed 428 participants aged 45 to 74 over a 16-week period. They were randomly assigned to receive either 10 μg of 25OHD daily or a placebo, all while maintaining a double-blind setup to ensure accurate results.
Our findings revealed that those who took 25OHD had reduced duration and severity of their cold symptoms. Participants reported improvements in their overall quality of life during the bouts of URTI. By tracking the health of the participants through surveys designed to measure cold symptoms, we gathered valuable data that indicates vitamin D3 could play a helpful role in managing colds.
This suggests that incorporating vitamin D3 into our diets may be beneficial when we catch a cold, potentially leading to a quicker recovery. It’s a promising avenue for anyone looking to ease the discomfort and duration of these frustrating infections.
Read More
7
Vitamin D's limited cold impact
High-dose oral vitamin D supplementation for prevention of infections in children aged 0 to 59 months: a systematic review and meta-analysis.
We evaluated the impact of high-dose vitamin D supplementation, specifically doses exceeding the standard 400 IU, on preventing colds and other infections in children under five years of age. Our analysis included seven studies, involving a total of 5,748 children, which looked into how effective vitamin D might be in reducing the incidence of upper respiratory tract infections.
Interestingly, while our findings showed no significant benefit of high-dose vitamin D on the prevention of upper respiratory tract infections as a whole, we did observe a noteworthy reduction in specific illness occurrences. We noted a 57% reduction in colds, a 56% reduction in coughs, and a 59% decrease in fever rates with daily doses exceeding 1,000 IU.
However, we must approach these findings with caution, as the evidence supporting the reduction in cough and fever was of lower certainty. No significant effects were observed regarding other conditions such as bronchitis or otitis media. Overall, while high-dose vitamin D may help with colds specifically, further research is needed to solidify these conclusions.
Read More
7
Vitamin D's role in Raynaud management
Serum vitamin B12 and D levels in children with Primary Raynaud Phenomenon: a retrospective cohort study.
We explored the impact of vitamin D and B12 deficiencies in children experiencing primary Raynaud phenomenon (RP), which causes temporary blood flow changes often triggered by cold or stress. Our study aimed to identify how common these vitamin deficiencies are in pediatric patients and whether they influenced the severity of Raynaud symptoms.
Out of 40 young participants, a significant portion—41.5% for vitamin B12 and 39% for vitamin D—showed low serum levels of these vitamins. After providing supplementation, we observed improved symptoms in many cases, particularly through warming techniques. However, it's important to note that while vasodilator treatment needs were generally unchanged regardless of vitamin B12 levels, those who had vitamin D deficiencies and subsequently received vitamin D treatment required significantly less vasodilator therapy.
Overall, while some positive effects of vitamin D were noted, further research is necessary to conclusively determine its role in managing primary RP symptoms and its effectiveness in combating cold-induced episodes.
Read More
7
Vitamin D reduces 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 effects of 25-hydroxyvitamin D (25OHD) on individuals experiencing upper respiratory tract infections (URTIs), commonly known as colds. In a well-structured study, participants with low vitamin D levels received either a daily dose of 10 micrograms of 25OHD or a placebo for a span of 16 weeks. The participants' symptoms were assessed using the Wisconsin Upper Respiratory Symptom Survey-21, focusing on how the vitamin impacted their cold symptoms.
Our findings showed that those taking 25OHD reported significant reductions in physical symptoms such as runny noses, sneezing, and head congestion compared to those on the placebo. Additionally, the quality of life scores improved for most symptoms, except for ease of breathing. However, it’s important to note that there was no significant difference in the total number of cold events or how often participants used medications like antibiotics or pain relievers.
Collectively, these results suggest that adequate intake of vitamin D can help ease cold symptoms, particularly those affecting the nose, and might enhance overall well-being when a cold strikes. This indicates that vitamin D may play a positive role in managing the discomfort associated with upper respiratory infections.
For temporary cold prevention, I take a single dose with vitamin K2 when someone near me has a cold. It appears to be effective. I ensure a week's gap between doses due to potential overdose risks, as noted on the manufacturer's site.
Read More
9
Boosts immunity
1 people found this helpful
I’ve been taking vitamin D3 for several months and the results have been remarkable. It has become essential to my daily routine, elevating my energy and mood significantly. My bones feel stronger and my joints are more mobile. During periods of virus activity, I feel more shielded, avoiding colds. This easy-to-take capsule provides a dose of sunshine that enhances my health daily.
Read More
9
Stops cold onset
1 people found this helpful
I mistakenly bought the wrong size, but when my family started feeling unwell, I took it. Thanks to this, I can prevent colds at their onset, making me very content.
Read More
9
Increased energy levels
Excellent! This high-potency vitamin D3 from NOW Foods has effectively corrected my vitamin D deficiency. I take one capsule weekly as my doctor advised. This dosage (50,000 IU) is ideal for restoring vitamin D levels after my test. After two months, my levels normalised, and I felt more energetic and resistant to colds. The soft capsules are easy to swallow, and the small pack of 50 suits a limited course of treatment.
Read More
9
Fights cold effectively
I take this more than once a week. NOW Foods Vitamin D-3 Max Potency is a game-changer for managing vitamin D deficiencies. Each softgel delivers a potent 50,000 IU, ideal for those on a high-potency regimen. They are small, easy to swallow, and leave no aftertaste, which is a major plus. After consistent use, I noticed significant improvements in my energy, mood, and symptoms like fatigue and muscle weakness, especially during colder months.
Cold is a term that refers to a state of low temperature, often associated with a perceptibly chilly environment or the sensation of being cool to the touch. Scientifically, cold is relative to the presence and movement of heat, which is a measure of energy within matter. In everyday terms, we experience cold through weather changes, such as during winter months, and it can also be described in the context of specific temperature ranges – for example, temperatures below 32 degrees Fahrenheit (0 degrees Celsius) generally signify freezing conditions, which can impact outdoor activities, personal comfort, and various ecological systems.
Moreover, the sensation of cold is not solely dependent on temperature; factors like humidity and wind chill can enhance the feeling of coldness. When discussing cold in terms of human health, prolonged exposure to cold conditions can lead to hypothermia or frostbite if body heat is not effectively maintained. Hence, it's crucial to dress appropriately and take necessary precautions during colder months to prevent adverse effects. Understanding the concept of cold can help individuals better prepare for seasonal changes and ensure their comfort and safety.
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 is often discussed in relation to immune health, and some studies suggest that it may play a role in reducing the risk of upper respiratory infections, including the common cold. Adequate levels of vitamin D might help enhance your immune response, potentially making your body more effective at fighting off infections. However, the evidence is not entirely conclusive, and while some individuals with low vitamin D levels may experience more frequent colds, it's important to consider that other factors also contribute to overall immunity, such as lifestyle and diet.
If you’re considering using vitamin D supplements to prevent or mitigate the effects of a cold, it’s always best to consult with a healthcare professional. They can provide tailored advice based on your specific health needs and possible deficiencies. While maintaining sufficient vitamin D levels can be beneficial for your immune system, it should not be seen as a guaranteed solution to avoid catching colds, especially during peak cold and flu seasons.
Based on user reviews, the time it takes to see results from taking this vitamin D supplement for cold prevention can vary. Some users report experiencing benefits almost immediately or within a few days of starting the supplement. For instance, one user noted they felt their immunity was boosted and recovered from a common cold with no symptoms after just two days of use Read Review. Others have observed significant improvements in their health and immunity within several weeks, emphasizing a noticeable reduction in colds and an overall feeling of increased energy Read Review.
In contrast, some users recommend maintaining consistent use over months for lasting results, with several reporting an overall improvement in their immune system and reduced cold frequency after several weeks to months of regular intake Read Review. A common thread among reviewers is that taking the supplement at the onset of cold symptoms helps in managing and potentially shortening the duration of illness Read Review. Overall, while immediate effects are possible, many users highlight the importance of continued use for longer-term benefits.
Vitamin D supplementation has garnered attention for its potential role in managing cold symptoms, particularly among children and individuals with low baseline levels of this vitamin. Research findings are somewhat mixed; while some studies indicate that high doses of vitamin D may result in significant reductions in the incidence of colds and coughs, as well as a decrease in fever rates among children, evidence remains tentative. For instance, one study reported a striking 57% reduction in colds with daily doses exceeding 1,000 IU, although the overall certainty of these findings is low [2].
In adult populations, research suggests that adequate vitamin D levels can alleviate symptoms associated with upper respiratory tract infections (URTIs). For example, participants in a study who received 10 micrograms daily of 25-hydroxyvitamin D reported notably lower symptoms, although the overall incidence of colds did not significantly differ from the placebo group [5]. Another study indicated that those with sufficient Vitamin D were 40% less likely to experience URTIs [4]. Collectively, the evidence hints at the potential for vitamin D to not only ease cold symptoms but also contribute to reducing the incidence of colds under certain conditions. However, more comprehensive research is warranted to firmly establish these effects.
Many users have reported significant improvements in their symptoms after incorporating this vitamin D supplement into their routines. For instance, one user shared that since starting vitamin D, they have drastically reduced their frequency of colds, only catching one every two years compared to their previous struggles with frequent infections Read Review. Another user emphasized that the supplement has elevated their energy levels and mood, while also providing a shield against colds during virus outbreaks Read Review.
Additionally, some users have noted immediate benefits; one user stated they experienced a remarkable recovery from a cold within just two days of taking the supplement Read Review. Reviewers often highlight the convenience and effectiveness of taking a high dosage weekly, enabling them to manage symptoms promptly and enhance overall immune function Read Review. It's essential to remember that individual results can vary, and maintaining consistent use over time might be necessary for achieving the best outcomes.
Users report positive experiences when combining this vitamin D supplement with other supplements for handling colds. One user mentioned that they effectively use the supplement alongside vitamin K2 for temporary cold prevention, suggesting that this combination appears effective during virus outbreaks Read Review. Another user stated they achieve enhanced results by combining vitamin D with vitamins B, C, and minerals, especially during a cold episode, indicating a synergistic effect that boosts immune response Read Review.
Additionally, several reviewers emphasized the importance of using vitamin D at the first signs of a cold to help manage symptoms and recover quicker, showcasing its role as a critical part of their regimen Read Review. The consistent use of this vitamin D supplement reportedly leads to fewer infections and shorter durations of illness, demonstrating its efficacy in combination with other health-supportive nutrients Read Review. Overall, users have found that such combinations not only enhance their immune systems but also provide a more comprehensive approach to navigating cold seasons effectively.
Recent research suggests that vitamin D may play a role in alleviating cold symptoms, especially for those with lower levels of this essential nutrient. Studies indicate that a daily dose of around 10 micrograms (or approximately 400 IU) of vitamin D3 may lead to significant improvements in cold symptoms, such as runny nose, sneezing, and head congestion. Participants in various trials specifically benefited from vitamin D supplementation, reporting reductions in physical symptoms associated with upper respiratory tract infections (URTIs) compared to placebo groups [5].
Moreover, higher doses of vitamin D, particularly those exceeding 1,000 IU daily, have demonstrated promise in reducing the incidence of colds. For instance, one study observed a striking 57% reduction in occurrences of colds among children taking higher doses [2]. However, while there are some positive correlations between vitamin D levels and a lesser severity of cold symptoms, it is vital to note that not all research conferred the same level of benefit, highlighting the necessity for additional studies to solidify optimal dosing recommendations. Overall, ensuring adequate levels of vitamin D might be key to easing cold symptoms and potentially shortening the duration of sickness.
9
Immediate effect
Very good. Its effect was immediate. The packaging was excellent. I didn’t need to sunbathe for a week after taking it. My immunity seemed boosted as I recovered from a common cold with no symptoms after two days. There was no unpleasant taste, and the small size made it very easy to consume.
9
Less frequent colds
Excellent! I ordered NOW Foods Vitamin D-3 softgels to boost my vitamin D levels, as advised by my doctor. I take one capsule weekly, which is easy to swallow and odourless. After several weeks, I've noticed improvements in alertness and mood and became less prone to frequent colds.
9
Increased energy levels
Excellent! This high-potency vitamin D3 from NOW Foods has effectively corrected my vitamin D deficiency. I take one capsule weekly as my doctor advised. This dosage (50,000 IU) is ideal for restoring vitamin D levels after my test. After two months, my levels normalised, and I felt more energetic and resistant to colds. The soft capsules are easy to swallow, and the small pack of 50 suits a limited course of treatment.
9
Prevents cold
With an excellent dosage of 50,000, taking one capsule weekly helps save both time and money. At the first signs of SARS, I take one capsule for 3-4 days, and the cold ends there.
9
Rare colds now
I love it! Vitamin D has significantly changed my health. Previously, I suffered from colds and chest infections almost constantly. Since starting vitamin D, I catch a cold maybe once every two years!
9
Boosts immunity
1 people found this helpful
I’ve been taking vitamin D3 for several months and the results have been remarkable. It has become essential to my daily routine, elevating my energy and mood significantly. My bones feel stronger and my joints are more mobile. During periods of virus activity, I feel more shielded, avoiding colds. This easy-to-take capsule provides a dose of sunshine that enhances my health daily.
7.5
Cold prevention
3 people found this helpful
For temporary cold prevention, I take a single dose with vitamin K2 when someone near me has a cold. It appears to be effective. I ensure a week's gap between doses due to potential overdose risks, as noted on the manufacturer's site.
8.5
Good effect
Using the 50,000 IU maximum dose of Vitamin D3 for three years, recommended by my doctor, has kept my ARVI occurrences low and provided good effects, particularly when combined with vitamins B, C, and minerals during a cold.
9
Helps with cold
A high-quality product, it works wonders when used at the first signs of a cold, helping me stay healthy and strengthening my immune system.
7
Vitamin D's limited cold impact
High-dose oral vitamin D supplementation for prevention of infections in children aged 0 to 59 months: a systematic review and meta-analysis.
We evaluated the impact of high-dose vitamin D supplementation, specifically doses exceeding the standard 400 IU, on preventing colds and other infections in children under five years of age. Our analysis included seven studies, involving a total of 5,748 children, which looked into how effective vitamin D might be in reducing the incidence of upper respiratory tract infections.
Interestingly, while our findings showed no significant benefit of high-dose vitamin D on the prevention of upper respiratory tract infections as a whole, we did observe a noteworthy reduction in specific illness occurrences. We noted a 57% reduction in colds, a 56% reduction in coughs, and a 59% decrease in fever rates with daily doses exceeding 1,000 IU.
However, we must approach these findings with caution, as the evidence supporting the reduction in cough and fever was of lower certainty. No significant effects were observed regarding other conditions such as bronchitis or otitis media. Overall, while high-dose vitamin D may help with colds specifically, further research is needed to solidify these conclusions.
7
Vitamin D reduces 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 effects of 25-hydroxyvitamin D (25OHD) on individuals experiencing upper respiratory tract infections (URTIs), commonly known as colds. In a well-structured study, participants with low vitamin D levels received either a daily dose of 10 micrograms of 25OHD or a placebo for a span of 16 weeks. The participants' symptoms were assessed using the Wisconsin Upper Respiratory Symptom Survey-21, focusing on how the vitamin impacted their cold symptoms.
Our findings showed that those taking 25OHD reported significant reductions in physical symptoms such as runny noses, sneezing, and head congestion compared to those on the placebo. Additionally, the quality of life scores improved for most symptoms, except for ease of breathing. However, it’s important to note that there was no significant difference in the total number of cold events or how often participants used medications like antibiotics or pain relievers.
Collectively, these results suggest that adequate intake of vitamin D can help ease cold symptoms, particularly those affecting the nose, and might enhance overall well-being when a cold strikes. This indicates that vitamin D may play a positive role in managing the discomfort associated with upper respiratory infections.
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 upper respiratory tract infections (URTIs) among military recruits during their training. This observation spanned across different seasons and included over 1,600 recruits. Our aim was to understand how achieving sufficient vitamin D levels could potentially impact the frequency and severity of colds among physically active individuals.
In an additional phase of the research, we conducted a randomized controlled trial with 250 male recruits. They received either a placebo, simulated sunlight exposure, or oral vitamin D3 supplements during winter. This comparison allowed us to see if these methods effectively increased vitamin D levels to a sufficient status of 25(OH)D at 50 nmol/L or higher.
Notably, our findings showed that only 21% of recruits had adequate vitamin D during winter, yet those who did were 40% less likely to suffer from URTIs. Furthermore, both vitamin D supplementation strategies similarly helped nearly all participants achieve sufficient levels. Vitamin D supplementation notably reduced the severity of URTI symptoms by 15% and the number of days with URTIs by 36% compared to placebo.
While the supplementation strategies did not significantly alter other immune factors, such as salivary secretory immunoglobulin A, the overall reduction in respiratory infections indicates a beneficial effect of maintaining vitamin D sufficiency during military training.
References
Marusca LM, Reddy G, Blaj M, Prathipati R, Rosca O, et al. The Effects of Vitamin D Supplementation on Respiratory Infections in Children under 6 Years Old: A Systematic Review. Diseases. 2023;11. 10.3390/diseases11030104
Carboo JA, Dolman-Macleod RC, Malan L, Lombard MJ. High-dose oral vitamin D supplementation for prevention of infections in children aged 0 to 59 months: a systematic review and meta-analysis. Nutr Rev. 2024;82:579. 10.1093/nutrit/nuad082
Kisla Ekinci RM, Taskin Karacay IE, Celik U. Serum vitamin B12 and D levels in children with Primary Raynaud Phenomenon: a retrospective cohort study. Eur J Clin Nutr. 2022;76:1615. 10.1038/s41430-022-01151-0
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. 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. 10.3390/nu12123769
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. 10.1007/s12603-017-0952-x