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
10
No colds since
1 people found this helpful
NOW Foods Vitamin D is a must-have for cold sufferers. My item arrived on time, and the seller was professional. Since I started taking these vitamin D tablets, I haven’t had a cold. I love the taste and would recommend them to family and friends suffering from colds.
Read More
9
Children's health boost
1 people found this helpful
Good things really recommended for children! Over the past two years, my three children have been taking these, and now they catch very few colds! Praise!
Read More
9
Child's immunity
One of the best! My child wakes better in the mornings, and we have navigated this autumn without colds! I attribute this improvement to this vitamin! It has also been a great support for my 7-year-old’s bones.
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.
NOW Foods Vitamin D is a must-have for cold sufferers. My item arrived on time, and the seller was professional. Since I started taking these vitamin D tablets, I haven’t had a cold. I love the taste and would recommend them to family and friends suffering from colds.
Read More
9
Children's health boost
1 people found this helpful
Good things really recommended for children! Over the past two years, my three children have been taking these, and now they catch very few colds! Praise!
Read More
9
Child's immunity
One of the best! My child wakes better in the mornings, and we have navigated this autumn without colds! I attribute this improvement to this vitamin! It has also been a great support for my 7-year-old’s bones.
Read More
9
Mild colds
Excellent vitamin D, which I ordered for my child to take from autumn to spring. When I notice signs of illness, I give two capsules instead of one, ensuring the cold passes in a mild form. I highly recommend this product and have reordered several times.
Read More
8
Cold relief
2 people found this helpful
Perfect D3! This safe dosage really works; I’ve noticed fewer colds and remarkably, my cold symptoms disappeared.
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 timeline for noticing results from taking this supplement for cold-related benefits can vary. Many users report experiencing improvements within just a few days of consistent use. For instance, one user mentioned feeling a surge of energy and alleviation of cold symptoms from the very first days of taking the vitamin D3, indicating quicker results (Read Review). Another user found that encouraging their children to take vitamin D3 consistently throughout the cold season helped them manage colds more easily, suggesting a gradual improvement in their immune response over time (Read Review).
However, some users noted that while the immediate alleviation of cold symptoms may not be evident, the overall improvement in their health and resilience to sickness becomes apparent over a longer duration. One review highlighted that the user couldn't pinpoint immediate effects but felt a sense of trust in the supplement's preventative capabilities (Read Review). Therefore, while users' experiences vary, a consistent daily intake appears to foster beneficial effects against colds, generally starting to show results within a few days to a couple of weeks.
The scientific research around vitamin D supplementation and its effects on cold symptoms presents a mix of findings. Some studies indicate that vitamin D can help alleviate symptoms associated with upper respiratory infections (URIs), commonly referred to as colds. For instance, research has shown that participants taking vitamin D3 reported significant reductions in cold symptoms like runny noses and sneezing, as well as an overall improvement in the quality of life during their illness ([5]). Another study suggests that adequate vitamin D levels could be linked to a substantial reduction in the incidence of URIs, with those receiving vitamin D3 experiencing a noteworthy decrease in the severity of these symptoms ([4]).
However, not all research points to strong preventative benefits. One analysis reported that high doses of vitamin D did not lead to significant reductions in the overall occurrence of colds among children, although some specific benefits were noted, such as a reduction in cough and fever ([2]). The prevailing consensus appears to be that while vitamin D may help in managing the severity and duration of cold symptoms, its role as a preventative measure against colds remains unclear and requires further investigation to establish conclusive benefits.
Based on user reviews, many individuals have reported significant improvements in their symptoms related to colds and respiratory health after using vitamin D3 supplements. One parent noted that their children had dramatically fewer colds over a two-year period, praising the product for its role in supporting their immune systems (Read Review). Another user mentioned their child waking up more refreshed and navigating autumn without any colds, attributing this success to the vitamin intake (Read Review). Users have also expressed that dosage adjustments, such as taking an extra capsule when noticing early signs of illness, helped mitigate symptoms effectively (Read Review).
Moreover, some users have shared that they experienced a reduction in cold symptoms and an enhancement in overall well-being, with improved energy levels and sleep quality attributable to consistent vitamin D3 use (Read Review). For example, one review noted feelings of increased strength and productivity within days of starting the regimen (Read Review). While individual results can vary, particularly in how quickly and strongly one might experience such benefits, the general consensus reflects a broad appreciation for this supplement’s potential in supporting respiratory health and immune function during cold and flu seasons.
Users have reported positive experiences when combining this vitamin D supplement with other supplements for handling colds. Specifically, several reviews mention the beneficial effects of pairing vitamin D with omega-3 supplements. One user noted that their daughter experienced fewer illnesses since starting this combination, going from being sick one week out of every month to being healthier overall while attending kindergarten (Read Review). This combination seemed to help in reducing the severity of cold symptoms, should they occur, and is praised for maintaining better health during the cold season.
Research suggests that vitamin D can play a role in alleviating cold symptoms, particularly when taken at adequate doses. One study indicated that children who took 800 IU of vitamin D daily for three months experienced fewer mild respiratory symptoms and recovered more quickly, while another highlighted that daily doses exceeding 1,000 IU resulted in a 57% reduction in cold incidence among participants [1][2]. Furthermore, various studies reported improvements in symptom severity and quality of life for individuals with low vitamin D who were supplemented with at least 10 micrograms (or 400 IU) of vitamin D3 [5][6].
While the optimal doses may vary depending on individual circumstances (such as age and baseline vitamin D levels), it appears that higher doses, particularly above 1,000 IU, could provide notable benefits in reducing the severity and duration of cold symptoms. This suggests that ensuring sufficient vitamin D levels, whether through diet, supplements, or sunlight, may be a beneficial strategy for managing the discomfort associated with colds [2][4]. However, further research is needed to establish definitive guidelines on the most effective doses for cold prevention and treatment.
9
Winter uplift
Good vitamins! I take D3 consistently during the cold season when there’s a lack of sun. A shortage of vitamin D3 makes me feel apathetic, lethargic and fatigued. However, taking vitamin D3 from this brand alleviates these issues completely. I feel a surge of strength and energy from the very first days, my sleep improves, and my productivity rises, even when it's cold outside.
7.5
Eases colds effectively
I always give this to children throughout the cold season. It helps them manage colds more easily. The capsules are small, making them easy for children to swallow.
6
Trustworthy vitamin D
I can't identify the immediate effects, but I feel a sense of trust. For hay fever, colds, and prevention against corona, continuing to take vitamin D seems to ease symptoms a little, and recovery appears quicker. I'm satisfied with the price and quantity, so I plan to continue its use.
9
Children's health boost
1 people found this helpful
Good things really recommended for children! Over the past two years, my three children have been taking these, and now they catch very few colds! Praise!
9
Child's immunity
One of the best! My child wakes better in the mornings, and we have navigated this autumn without colds! I attribute this improvement to this vitamin! It has also been a great support for my 7-year-old’s bones.
9
Mild colds
Excellent vitamin D, which I ordered for my child to take from autumn to spring. When I notice signs of illness, I give two capsules instead of one, ensuring the cold passes in a mild form. I highly recommend this product and have reordered several times.
7.5
Sick less often
My daughter is less sick since we began using vitamin D and omega-3. The soft capsules are easy for her to swallow, and we've observed no side effects. This has helped her maintain better health whilst attending kindergarten, going from one week a month to three weeks. If she does catch a cold, the symptoms are mild. I highly recommend this combination.
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.
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.
5
Vitamin D and cold symptoms
The Effects of Vitamin D Supplementation on Respiratory Infections in Children under 6 Years Old: A Systematic Review.
We explored the effects of vitamin D supplementation on respiratory infections, particularly colds, in children under six years old. By examining various studies published until February 2023, we observed diverse findings, with some studies reporting benefits while others found no significant advantage. Overall, eight studies were included, with a total of 2,189 children assessed.
While a few studies indicated that low vitamin D levels might be linked to an increased risk of respiratory infections, only one study specifically noted that children who took 800 IU of vitamin D daily for three months experienced fewer mild respiratory symptoms and recovered more quickly. However, a significant number of studies showed no notable differences in the rates or severity of colds when vitamin D supplementation was used.
In essence, the evidence regarding vitamin D's role in preventing or effectively treating colds in young children is still unclear. We did find some indications that certain doses, like 80 IU/kg/day, may help reduce acute respiratory infection risks, but most research highlighted only minor benefits, such as quicker recovery rather than preventing infections. Variability in study design and supplementation protocols contributed to these inconclusive results, highlighting the need for further research.
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.
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