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
10
No colds for years
1 people found this helpful
I order this dosage for summer; for the rest of the year, I take 2000 IU from the same manufacturer. The most important effect is that my whole family hasn't caught a cold for two years, and the usual crowned illness passed without symptoms. I've consistently maintained our vitamin levels.
Read More
9.5
Avoided flu
After learning about the benefits of vitamin D therapy on the immune system, I began taking it. With many sick classmates at school, my immune system weakened, so I increased my vitamin D intake during these sick times and avoided about 95% of the flu and colds around me.
Read More
9
Improves flu symptoms
Excellent dosage of vitamin D! I take it when I have the flu and feel better. I love this company and often order for myself and loved ones. A great replacement for sunlight during the cold season with convenient packaging. The effect of these vitamins is truly pleasing.
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 12 Reviews
8.3
All Reviews
Positive Reviews
Negative Reviews
10
No colds for years
1 people found this helpful
I order this dosage for summer; for the rest of the year, I take 2000 IU from the same manufacturer. The most important effect is that my whole family hasn't caught a cold for two years, and the usual crowned illness passed without symptoms. I've consistently maintained our vitamin levels.
Read More
9.5
Avoided flu
After learning about the benefits of vitamin D therapy on the immune system, I began taking it. With many sick classmates at school, my immune system weakened, so I increased my vitamin D intake during these sick times and avoided about 95% of the flu and colds around me.
Read More
9
Improves flu symptoms
Excellent dosage of vitamin D! I take it when I have the flu and feel better. I love this company and often order for myself and loved ones. A great replacement for sunlight during the cold season with convenient packaging. The effect of these vitamins is truly pleasing.
Read More
9
Supports cold treatment
Excellent! I ordered this dosage for my wife, as her test results indicated it’s essential to maintain the level. We typically reduce the dosage during summer, but when autumn arrives or we experience the first signs of a cold, we promptly increase to larger doses. In winter, we maintain a permanent dosage of 5, and during illness, we take 10-15 for a week.
Read More
7.5
Prevents seasonal colds
1 people found this helpful
I began taking NOW Foods Vegetarian Vitamin D a few months ago and wanted to share my experience. The package includes 120 vegetarian capsules, making it convenient for long-term use. I take one capsule daily, so it lasts for four months, offering great value. Since starting this vitamin D, I've noticed an improvement in my overall health. I had issues with my vitamin D levels, and the supplement effectively restored them. I feel more energetic and less susceptible to seasonal colds. The capsules are small and easy to swallow, and I take them with food for better absorption without experiencing side effects. I appreciate that it's vegetarian and free from artificial additives. NOW Foods is a reliable manufacturer, and I trust their product quality. I'm very pleased with the results and recommend it to anyone seeking a quality source of Vitamin D!
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 timeframe to see results from taking vitamin D supplements for cold prevention or treatment can vary, with many users reporting improvements almost immediately or within a few days of starting the regimen. For instance, one user mentioned that at the first sign of a cold, taking vitamin D along with zinc proved effective for them Read Review. Another review states that the user has noticed a significant reduction in the frequency of catching colds after a period of consistent use Read Review.
Additionally, some users have indicated that maintaining adequate levels of vitamin D throughout the year has led to fewer colds overall, showing that regular intake can bolster immune health and potentially prevent illness over time Read Review. Overall, while individual experiences may vary, many users emphasize the benefits realized soon after incorporating vitamin D into their routines, particularly during the cold season.
When it comes to vitamin D supplementation for cold prevention and symptom relief, scientific research presents a nuanced picture. Several studies have explored the potential benefits of vitamin D on upper respiratory tract infections (URTIs), commonly known as colds. Notably, a study involving military recruits found that vitamin D supplementation reduced the severity of URTI symptoms by 15% and decreased the number of days suffering from colds by 36% compared to a placebo group [4]. Another study indicated that participants with low vitamin D levels who received supplementation reported significant reductions in physical symptoms such as runny noses and sneezing, suggesting that vitamin D may indeed aid in alleviating cold symptoms [5].
However, research is mixed when it comes to vitamin D's role in preventing colds outright. A review of studies assessing high-dose vitamin D revealed a noteworthy reduction in the occurrence of colds (57% decrease) among children taking doses exceeding 1,000 IU daily, yet overall conclusions regarding prevention remain inconclusive due to variability and lower certainty of evidence [2]. For those specifically seeking relief from cold symptoms, maintaining adequate vitamin D levels may improve how individuals feel during infections, but definitive claims about preventing colds entirely warrant more investigation to fully understand vitamin D's efficacy in this area.
Based on user reviews, many individuals have reported notable improvements in their cold prevention and overall health since incorporating vitamin D into their routines. Several users highlighted that consistent use of vitamin D has significantly reduced their frequency of catching colds. For instance, one user shared that their family has not experienced a cold for two years by maintaining adequate vitamin D levels Read Review. Another reviewer emphasized that during cold season, an increase in their vitamin D intake allowed them to avoid about 95% of the illnesses around them, showcasing a strong correlation between vitamin D intake and immune resilience Read Review.
Additionally, users have reported feeling more energetic and in better overall health after starting vitamin D supplements. One review noted that since their vitamin D levels were restored, they have felt less susceptible to seasonal colds and improved their overall vitality, particularly in the colder months Read Review. While individual results can vary, these anecdotal experiences suggest that vitamin D may play a crucial role in enhancing immune function and improving well-being during colder seasons.
Based on user reviews, many individuals have reported success in combining vitamin D with other supplements to effectively handle colds. For instance, one user noted that at the first sign of a cold, they take vitamin D in conjunction with zinc, indicating that this combination is beneficial for preventing them from getting sick Read Review. Similarly, another reviewer stated they experienced relief from early cold symptoms when pairing vitamin D with zinc and vitamin C, further emphasizing the effectiveness of these combinations in bolstering immune response during illness Read Review.
Additional feedback highlights that maintaining a routine of vitamin D supplementation, especially during colder months, contributes positively to overall health and reduced frequency of colds. One user shared that they typically increase their vitamin D dosage during autumn or when experiencing the first signs of a cold, which has proven effective for them Read Review. Overall, users seem to benefit from a holistic approach to cold prevention by integrating vitamin D with other supportive supplements, allowing for enhanced immune support during cold season.
When it comes to using vitamin D as a potential remedy for colds, research suggests that there are varying opinions on the optimal dosing. In a study focusing on children, a daily dose of 800 IU for three months was associated with fewer mild respiratory symptoms and quicker recovery from colds [1]. Another analysis indicated that higher doses exceeding 1,000 IU daily led to significant reductions in the incidence of colds and related symptoms, with results showing decreases of up to 57% in cold cases [2]. This suggests that while lower doses may have some benefits, higher doses could be more effective for certain age groups.
However, it's essential to approach these findings with caution. The evidence for vitamin D's role in preventing colds remains inconclusive, with some studies showing only minor benefits and variability in outcomes [1]. For adults, certain studies indicate that adequate intake—despite not being definitively linked to preventing colds—can significantly ease cold symptoms and improve overall quality of life when diseases arise [5]. As always, consulting with a healthcare provider before starting any new supplementation is recommended, particularly to determine the best dosing specific to individual health needs and conditions.
7.5
Prevents illness
1 people found this helpful
At the first sign of a cold, I drink it with zinc. Great for preventing me from getting sick.
7.5
Fewer colds
I've been taking it for quite some time now and find I catch colds less often.
10
No colds for years
1 people found this helpful
I order this dosage for summer; for the rest of the year, I take 2000 IU from the same manufacturer. The most important effect is that my whole family hasn't caught a cold for two years, and the usual crowned illness passed without symptoms. I've consistently maintained our vitamin levels.
9.5
Avoided flu
After learning about the benefits of vitamin D therapy on the immune system, I began taking it. With many sick classmates at school, my immune system weakened, so I increased my vitamin D intake during these sick times and avoided about 95% of the flu and colds around me.
7.5
Prevents seasonal colds
1 people found this helpful
I began taking NOW Foods Vegetarian Vitamin D a few months ago and wanted to share my experience. The package includes 120 vegetarian capsules, making it convenient for long-term use. I take one capsule daily, so it lasts for four months, offering great value. Since starting this vitamin D, I've noticed an improvement in my overall health. I had issues with my vitamin D levels, and the supplement effectively restored them. I feel more energetic and less susceptible to seasonal colds. The capsules are small and easy to swallow, and I take them with food for better absorption without experiencing side effects. I appreciate that it's vegetarian and free from artificial additives. NOW Foods is a reliable manufacturer, and I trust their product quality. I'm very pleased with the results and recommend it to anyone seeking a quality source of Vitamin D!
7.5
Effective for colds
Help at the first signs of a cold and ARVI, in combination with zinc and vitamin C.
9
Supports cold treatment
Excellent! I ordered this dosage for my wife, as her test results indicated it’s essential to maintain the level. We typically reduce the dosage during summer, but when autumn arrives or we experience the first signs of a cold, we promptly increase to larger doses. In winter, we maintain a permanent dosage of 5, and during illness, we take 10-15 for a week.
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 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.
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.
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. doi: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. doi: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. doi: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. doi:10.1249/MSS.0000000000002604
Shimizu Y, Ito Y, Uotsu N, Yui K. Intake of 25-Hydroxyvitamin D May Reduce the Severity of Upper Respiratory Tract Infection: Post hoc Analysis of a Randomized, Double-Blind, Placebo-Controlled, Parallel Group Comparison Study. Nutrients. 2020;12. doi:10.3390/nu12123769