Last update
4/4/2026
Reviewed By
Overview
SCIENTIFIC SCORE
Questionable
Based on 4 Researches
6.4
USERS' SCORE
Good
Based on 161 Reviews
8.2
Supplement Facts
Serving Size: 1 Softgel
Amount Per Serving
%DV
Vitamin D3 (as Cholecalciferol) (from Lanolin)
125 mcg (5,000 IU)
625%
Top Medical Research Studies
0
We conducted a study to see if high-dose vitamin D3 could improve vascular health and reduce fatigue in individuals suffering from chronic fatigue syndrome (CFS). This was a well-structured trial involving 50 participants, all of whom met specific diagnostic criteria for CFS. Participants were divided into two groups: one received 100,000 units of vitamin D3 every two months, while the other received a placebo over a period of six months.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
Read More
9.5
Vitamin D treatment enhances alertness
We explored the impact of vitamin D treatment on a case of excessive daytime sleepiness (EDS), specifically in the context of chronic fatigue syndrome. A 28-year-old woman was found to have low levels of vitamin D after experiencing four months of overwhelming fatigue and sleepiness, despite being tested for sleep disorders.
After starting vitamin D supplementation, her condition improved remarkably within just two weeks. Along with a boost in alertness, her associated symptoms like muscle pain and headaches began to fade. By the end of the treatment, her score on the Epworth Sleepiness Scale, which measures daytime sleepiness, dropped significantly, indicating much better daytime function.
This case suggests that vitamin D may play a role in improving symptoms commonly linked to chronic fatigue syndrome. While more research is needed to fully understand the mechanisms behind this improvement, our findings open the door to potentially screening patients with chronic fatigue for vitamin D deficiency to expedite treatment.
After starting vitamin D supplementation, her condition improved remarkably within just two weeks. Along with a boost in alertness, her associated symptoms like muscle pain and headaches began to fade. By the end of the treatment, her score on the Epworth Sleepiness Scale, which measures daytime sleepiness, dropped significantly, indicating much better daytime function.
This case suggests that vitamin D may play a role in improving symptoms commonly linked to chronic fatigue syndrome. While more research is needed to fully understand the mechanisms behind this improvement, our findings open the door to potentially screening patients with chronic fatigue for vitamin D deficiency to expedite treatment.
Read More
8
We conducted a double-blind, placebo-controlled trial to evaluate the effects of an oral food supplement (OFS) on long COVID patients, particularly focusing on chronic inflammation and fatigue. The supplement included components like rosehip, propolis, royal jelly, and zinc, with vitamin C being a key ingredient.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
Read More
Most Useful Reviews
9
Chronic fatigue alleviated
174 people found this helpful
Upon discovering I was deficient, I began taking Vitamin D3, which nearly eliminated my chronic fatigue syndrome. I highly recommend getting tested and ensuring proper vitamin intake.
Read More
9
Enhanced workout stamina
105 people found this helpful
Initially sceptical about vitamins, after taking D3 for half a year alongside Omega and iron, I've forgotten the feeling of chronic fatigue syndrome. Workouts are much easier, allowing me to endure even cardio, which I once despised.
Read More
9
Mood improvement
90 people found this helpful
After just two weeks of using this vitamin, my chronic fatigue syndrome has improved significantly. I no longer feel fatigued, and my mood has brightened. It's been challenging to find quality supplements, but this one is definitely worth it!
Read More
Medical Researches
SCIENTIFIC SCORE
Questionable
Based on 4 Researches
6.4
- All Researches
9.5
Vitamin D treatment enhances alertness
We explored the impact of vitamin D treatment on a case of excessive daytime sleepiness (EDS), specifically in the context of chronic fatigue syndrome. A 28-year-old woman was found to have low levels of vitamin D after experiencing four months of overwhelming fatigue and sleepiness, despite being tested for sleep disorders.
After starting vitamin D supplementation, her condition improved remarkably within just two weeks. Along with a boost in alertness, her associated symptoms like muscle pain and headaches began to fade. By the end of the treatment, her score on the Epworth Sleepiness Scale, which measures daytime sleepiness, dropped significantly, indicating much better daytime function.
This case suggests that vitamin D may play a role in improving symptoms commonly linked to chronic fatigue syndrome. While more research is needed to fully understand the mechanisms behind this improvement, our findings open the door to potentially screening patients with chronic fatigue for vitamin D deficiency to expedite treatment.
After starting vitamin D supplementation, her condition improved remarkably within just two weeks. Along with a boost in alertness, her associated symptoms like muscle pain and headaches began to fade. By the end of the treatment, her score on the Epworth Sleepiness Scale, which measures daytime sleepiness, dropped significantly, indicating much better daytime function.
This case suggests that vitamin D may play a role in improving symptoms commonly linked to chronic fatigue syndrome. While more research is needed to fully understand the mechanisms behind this improvement, our findings open the door to potentially screening patients with chronic fatigue for vitamin D deficiency to expedite treatment.
Read More
8
We conducted a double-blind, placebo-controlled trial to evaluate the effects of an oral food supplement (OFS) on long COVID patients, particularly focusing on chronic inflammation and fatigue. The supplement included components like rosehip, propolis, royal jelly, and zinc, with vitamin C being a key ingredient.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
Read More
8
Beta-glucan shows cognitive improvements
We conducted a randomized, double-blind, placebo-controlled trial to explore how yeast beta-glucan, along with multivitamins, affects individuals suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). In our study, 65 participants received either beta-glucan combined with vitamins and zinc or a placebo for 36 weeks.
Interestingly, while our primary focus was on beta-glucan, which was shown to significantly improve cognitive fatigue, the role of vitamin D3 within this combination was not clearly established. This makes it challenging to directly assess the impact of vitamin D3 alone on chronic fatigue syndrome outcomes.
Overall, we discovered that beta-glucan supplementation could positively influence cognitive fatigue, offering promise for future research on nutritional support in ME/CFS patients. However, definitive conclusions about vitamin D3's effectiveness remain inconclusive due to the combined nature of the treatment.
Interestingly, while our primary focus was on beta-glucan, which was shown to significantly improve cognitive fatigue, the role of vitamin D3 within this combination was not clearly established. This makes it challenging to directly assess the impact of vitamin D3 alone on chronic fatigue syndrome outcomes.
Overall, we discovered that beta-glucan supplementation could positively influence cognitive fatigue, offering promise for future research on nutritional support in ME/CFS patients. However, definitive conclusions about vitamin D3's effectiveness remain inconclusive due to the combined nature of the treatment.
Read More
0
We conducted a study to see if high-dose vitamin D3 could improve vascular health and reduce fatigue in individuals suffering from chronic fatigue syndrome (CFS). This was a well-structured trial involving 50 participants, all of whom met specific diagnostic criteria for CFS. Participants were divided into two groups: one received 100,000 units of vitamin D3 every two months, while the other received a placebo over a period of six months.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
Read More
User Reviews
USERS' SCORE
Good
Based on 161 Reviews
8.2
- All Reviews
- Positive Reviews
- Negative Reviews
9
Chronic fatigue alleviated
174 people found this helpful
Upon discovering I was deficient, I began taking Vitamin D3, which nearly eliminated my chronic fatigue syndrome. I highly recommend getting tested and ensuring proper vitamin intake.
Read More
9
Enhanced workout stamina
105 people found this helpful
Initially sceptical about vitamins, after taking D3 for half a year alongside Omega and iron, I've forgotten the feeling of chronic fatigue syndrome. Workouts are much easier, allowing me to endure even cardio, which I once despised.
Read More
9
Mood improvement
90 people found this helpful
After just two weeks of using this vitamin, my chronic fatigue syndrome has improved significantly. I no longer feel fatigued, and my mood has brightened. It's been challenging to find quality supplements, but this one is definitely worth it!
Read More
7.5
Stronger immune system
90 people found this helpful
Taking vitamin D alongside omega-3 has noticeably enhanced my immune system. My hair loss has decreased, and my nails are in excellent condition. When I stop taking them, I feel the fatigue return.
Read More
7.5
Increased energy levels
90 people found this helpful
I have been taking this vitamin for the past month and can already feel a difference. I feel more energetic, have more stamina, and less fatigue. It's also beneficial for my skin and hair. Definitely worth every penny!
Read More
Frequently Asked Questions
9
Mood improvement
90 people found this helpful
After just two weeks of using this vitamin, my chronic fatigue syndrome has improved significantly. I no longer feel fatigued, and my mood has brightened. It's been challenging to find quality supplements, but this one is definitely worth it!
9
Chronic fatigue alleviated
174 people found this helpful
Upon discovering I was deficient, I began taking Vitamin D3, which nearly eliminated my chronic fatigue syndrome. I highly recommend getting tested and ensuring proper vitamin intake.
7.5
Stronger immune system
90 people found this helpful
Taking vitamin D alongside omega-3 has noticeably enhanced my immune system. My hair loss has decreased, and my nails are in excellent condition. When I stop taking them, I feel the fatigue return.
9
Enhanced workout stamina
105 people found this helpful
Initially sceptical about vitamins, after taking D3 for half a year alongside Omega and iron, I've forgotten the feeling of chronic fatigue syndrome. Workouts are much easier, allowing me to endure even cardio, which I once despised.
9
Boosted energy
3 people found this helpful
Excellent vitamin D3 with no side effects! I'm following my hematologist's advice to take 5,000 IU daily. From the first week, I noticed significant improvements—it's easier to wake up, and the chronic fatigue syndrome I experienced is gone.
0
We conducted a study to see if high-dose vitamin D3 could improve vascular health and reduce fatigue in individuals suffering from chronic fatigue syndrome (CFS). This was a well-structured trial involving 50 participants, all of whom met specific diagnostic criteria for CFS. Participants were divided into two groups: one received 100,000 units of vitamin D3 every two months, while the other received a placebo over a period of six months.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
Despite a noticeable increase of 22 nmol/L in vitamin D levels for those who received the treatment compared to the placebo group, we found no significant benefits. There was no change in arterial stiffness, a key vascular health indicator, nor improvements in overall fatigue as measured by the Piper Fatigue scale.
In essence, our findings indicate that high-dose oral vitamin D3 does not offer the hoped-for relief in vascular function or fatigue for patients with chronic fatigue syndrome. This suggests that other therapeutic options may need to be explored for individuals suffering from this condition.
8
We conducted a double-blind, placebo-controlled trial to evaluate the effects of an oral food supplement (OFS) on long COVID patients, particularly focusing on chronic inflammation and fatigue. The supplement included components like rosehip, propolis, royal jelly, and zinc, with vitamin C being a key ingredient.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
Through our two-month study, which involved giving participants either the OFS or a placebo, we made some interesting observations. Notably, patients who took the OFS experienced a significant reduction in inflammatory markers, which are often linked to chronic fatigue syndrome. This included improvements in the neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios.
We also noted a substantial increase in vitamin D levels among those taking the supplement, which correlated with enhanced quality of life and decreased fatigue as measured by the fatigue severity scale. Our findings suggest that the combination of ingredients in the OFS, particularly its vitamin D content, can help alleviate some symptoms associated with long COVID, especially chronic fatigue.
However, since the supplement included multiple active ingredients, isolating the specific impact of vitamin D on chronic fatigue syndrome is challenging. Still, the overall results indicate positive changes for patients dealing with the lingering effects of COVID.
References
- Noce A, Marrone G, Di Lauro M, Vita C, Montalto G, et al. Potential Anti-Inflammatory and Anti-Fatigue Effects of an Oral Food Supplement in Long COVID Patients. Pharmaceuticals (Basel). 2024;17. 10.3390/ph17040463
- Witham MD, Adams F, McSwiggan S, Kennedy G, Kabir G, et al. Effect of intermittent vitamin D3 on vascular function and symptoms in chronic fatigue syndrome--a randomised controlled trial. Nutr Metab Cardiovasc Dis. 2015;25:287. 10.1016/j.numecd.2014.10.007
- McCarty DE. Resolution of hypersomnia following identification and treatment of vitamin d deficiency. J Clin Sleep Med. 2010;6:605. PubMed
- Lacasa M, Alegre-Martin J, Sentañes RS, Varela-Sende L, Jurek J, et al. Yeast Beta-Glucan Supplementation with Multivitamins Attenuates Cognitive Impairments in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients. 2023;15. 10.3390/nu15214504
Data last updated:
