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
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 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.
Read More
Most Useful Reviews
9
Immunity boost
100 people found this helpful
An excellent vitamin complex to maintain immunity; it significantly helps my family during colds.
Read More
9
Strong protection
6 people found this helpful
Perfectly! I order this for the second time. Vitamin D regulates calcium and phosphorus absorption. It protects the body from colds and various diseases. Symptoms of vitamin D deficiency include loss of appetite, insomnia, and more. Taking it with calcium and fish oil has given me great results.
Read More
7.5
Improved mood
2 people found this helpful
Fast dissolving drug. I regularly take vitamins, especially vitamin D. Its major advantage is that it dissolves quickly in the mouth without needing to be swallowed. For me, vitamin D helps me cope with the autumn-winter season. Without it, I struggle to get out of bed and often feel apathetic and weak during the day. With vitamin D, I wake up easily without an alarm clock, and the cold does not frighten me or upset me.
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
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.
Read More
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.
Read More
User Reviews
USERS' SCORE
Good
Based on 32 Reviews
8.6
All Reviews
Positive Reviews
Negative Reviews
9
Immunity boost
100 people found this helpful
An excellent vitamin complex to maintain immunity; it significantly helps my family during colds.
Read More
9
Strong protection
6 people found this helpful
Perfectly! I order this for the second time. Vitamin D regulates calcium and phosphorus absorption. It protects the body from colds and various diseases. Symptoms of vitamin D deficiency include loss of appetite, insomnia, and more. Taking it with calcium and fish oil has given me great results.
Read More
7.5
Improved mood
2 people found this helpful
Fast dissolving drug. I regularly take vitamins, especially vitamin D. Its major advantage is that it dissolves quickly in the mouth without needing to be swallowed. For me, vitamin D helps me cope with the autumn-winter season. Without it, I struggle to get out of bed and often feel apathetic and weak during the day. With vitamin D, I wake up easily without an alarm clock, and the cold does not frighten me or upset me.
Read More
10
Prevents cold effectively
This is the most potent D3 I've tried. After a two-week intake, my strength returned and my mood improved. Now I only drink it when I feel the first symptoms of a cold, and within a couple of days, everything disappears. It stops me from getting sick, whereas previously, I would have been ill if anyone sneezed nearby. In general, I recommend it.
Read More
9
Effective remedy
Excellent D3! Small yet effective. We take one tablet in the morning after breakfast. At the first sign of a cold, we take 5-7 tablets daily with zinc, and the illness recedes in just 1-2 days! The same dosage is given to children at the first sign of a cold.
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 vitamin D supplements, particularly in combating colds, can vary. Several users noted that they experienced noticeable improvements in their well-being and immunity within a few days. For example, one user mentioned that after a two-week intake, their strength returned, and by taking it at the first symptoms of a cold, they found symptoms disappearing in a couple of days Read Review. Another user reported that increasing their intake to 5-7 tablets daily at the first sign of a cold helped the illness recede in just 1-2 days Read Review.
Many reviewers emphasized the importance of the supplement in preventing colds and enhancing overall immunity, with some claiming that they hadn't experienced a cold in months after regular use Read Review. The consensus appears to indicate that users can expect to see benefits quite quickly, especially when starting the supplement at the onset of illness.
Vitamin D supplementation has garnered attention for its potential effects on cold symptoms, particularly in young children and military recruits. Studies indicate mixed outcomes regarding its efficacy in preventing or treating colds. For instance, research involving young children found only minor benefits, such as quicker recovery from mild respiratory symptoms with 800 IU of vitamin D daily [1]. On the other hand, a study highlighting higher doses (exceeding 1,000 IU) suggested notable reductions in the incidence of colds by 57% and coughs by 56% [2]. Still, the evidence remains inconclusive, with calls for more rigorous research to solidify these findings.
Additional investigations have pointed to the potential positive impacts of vitamin D on alleviating cold symptoms. A controlled trial demonstrated that participants receiving vitamin D supplementation experienced a significant reduction in cold symptoms, particularly nasal complications [5]. This aligns with findings indicating that maintaining adequate vitamin D levels significantly decreased the frequency and severity of upper respiratory tract infections among military recruits [4]. Although these studies present promising insights, it’s essential to interpret the results cautiously and acknowledge the need for further investigations to fully understand vitamin D’s role in cold management.
Users report a variety of improvements in symptoms when taking vitamin D supplements, particularly regarding colds and overall well-being. Many mention that the supplements effectively enhance their immune response during the colder months. A user highlighted that they haven't experienced a cold in five months, crediting this positive change to regular vitamin D intake, contrasting with their previous frequency of colds every couple of months Read Review. Another user found that taking higher doses at the first sign of a cold helped symptoms recede in just 1-2 days, a sentiment echoed by others who experienced quick recoveries after increasing their dosage during illness Read Review.
Additionally, several reviews indicate significant improvements in energy levels, mood, and overall health, especially during winter months. For instance, one user reported feeling less apathetic and weak, and instead, waking up easily without the need for an alarm Read Review. Another noted enhanced immunity and decreased illness frequency after integrating vitamin D into their routine Read Review. While individual results can vary, the collective feedback suggests that many users find vitamin D to be a beneficial tool in maintaining their immunity and overall health.
Users frequently report positive synergies when combining this vitamin D supplement with other nutrients aimed at enhancing immunity, particularly during cold season. Many have noted significant improvements in their health when taking vitamin D alongside options like zinc and vitamin C. One user shared that at the first sign of a cold, they take 5-7 tablets of vitamin D daily along with zinc, resulting in a rapid recovery within 1-2 days Read Review. Another echoed this sentiment, stating that increasing the dosage of vitamin D in combination with vitamin C for their child led to noticeable effects Read Review.
Users also expressed that the supplement can be an effective preventative measure against colds when included in a daily regimen, further boosted by additional vitamins. One user commented on the importance of combining vitamin D with calcium and fish oil, creating a comprehensive approach to immune health Read Review. Collectively, these testimonials suggest that incorporating vitamin D with other supportive supplements could lead to faster recoveries from cold symptoms and enhanced overall wellness during the colder months.
The optimal dose of Vitamin D for treating colds appears to vary based on different studies, but a few key findings stand out. For children, one study noted that a daily supplementation of 800 IU for three months led to a reduction in mild respiratory symptoms and quicker recovery from colds [1]. Another significant study indicated that high doses exceeding 1,000 IU daily could result in substantial reductions in cold incidence—specifically, a 57% decrease in colds among young children [2]. However, it’s important to note that while some benefits were observed, the overall evidence remains inconclusive and suggests further research is necessary to pinpoint an optimal dosing strategy.
For adults, one study highlighted that a daily intake of 10 micrograms (equivalent to 400 IU) of Vitamin D resulted in significant reductions in upper respiratory symptoms like runny noses and sneezing, compared to a placebo group [5]. This suggests that ensuring adequate Vitamin D levels may alleviate cold symptoms and improve overall comfort during respiratory infections. Ultimately, it seems keeping Vitamin D levels within a sufficient range is beneficial, but individuals should consult healthcare professionals to determine personalized dosing strategies.
10
Prevents cold effectively
This is the most potent D3 I've tried. After a two-week intake, my strength returned and my mood improved. Now I only drink it when I feel the first symptoms of a cold, and within a couple of days, everything disappears. It stops me from getting sick, whereas previously, I would have been ill if anyone sneezed nearby. In general, I recommend it.
9
Cold-free months
I now take this vitamin regularly. It has no taste, the tablet is small, and dissolves easily under the tongue. The high dosage of 5000 units, along with plenty of tablets in a pack, lasts a long time. Most importantly, I haven’t had any colds in 5 months, which used to occur every 2-3 months. I attribute this improvement to the vitamin, and I will be ordering more.
9
Effective remedy
Excellent D3! Small yet effective. We take one tablet in the morning after breakfast. At the first sign of a cold, we take 5-7 tablets daily with zinc, and the illness recedes in just 1-2 days! The same dosage is given to children at the first sign of a cold.
7.5
Improved mood
2 people found this helpful
Fast dissolving drug. I regularly take vitamins, especially vitamin D. Its major advantage is that it dissolves quickly in the mouth without needing to be swallowed. For me, vitamin D helps me cope with the autumn-winter season. Without it, I struggle to get out of bed and often feel apathetic and weak during the day. With vitamin D, I wake up easily without an alarm clock, and the cold does not frighten me or upset me.
8
Fast-acting vitamin
If you want to quickly boost your vitamin D3 levels, this is a very effective product! The sublingual form raises vitamin D3 levels swiftly. The tablets are tiny, dissolving quickly under the tongue. The dosage is ideal for replenishing vitamin D3. I’ve doubled my immune system strength, leading to fewer colds, even after being exposed to drafts previously. I highly recommend it!
9
Regular purchase
I constantly purchase this vitamin D, which I find excellent. It dissolves quickly under the tongue and has a sweetish taste. We follow a regimen of taking it daily for a week, then twice more every other day, and afterwards 2-3 times weekly to maintain our vitamin D levels. During the cold season, I give it to my child. Combined with vitamin C and children's zinc, it works wonders.
9
Strong protection
6 people found this helpful
Perfectly! I order this for the second time. Vitamin D regulates calcium and phosphorus absorption. It protects the body from colds and various diseases. Symptoms of vitamin D deficiency include loss of appetite, insomnia, and more. Taking it with calcium and fish oil has given me great results.
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.
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