Scientists discover strange link between vitamin D and pain

In continuation of my update on Vitamin D 

Women with low vitamin D levels may face a more painful recovery after breast cancer surgery and could require significantly more opioid medication afterward, according to research published online in the journal Regional Anesthesia & Pain Medicine.

The findings suggest that breast cancer patients with vitamin D deficiency (below 30 nmol/L) might benefit from taking vitamin D supplements before undergoing a radical mastectomy.

Researchers say growing evidence points to vitamin D playing an important role in how the body senses and regulates pain. Scientists believe this may be connected to the vitamin's anti inflammatory properties and its effects on the immune system. Vitamin D deficiency is also frequently seen in people with breast cancer.

Study Examined Pain After Breast Cancer Surgery

To explore the connection, researchers carried out a prospective observational study at Fayoum University Hospital in Egypt between September 2024 and April 2025.

The study included 184 women with breast cancer who were preparing to have surgery to remove one breast. Half of the participants had vitamin D deficiency (below 30 nmol/L), while the other half had vitamin D levels above 30 nmol/L. The two groups were otherwise similar, with average ages of 44 and 42.

Doctors and nurses caring for the patients did not know their vitamin D status. All participants received the hospital's standard treatment before, during, and after surgery.

During the operation, patients were given fentanyl to control acute pain. After surgery, everyone received intravenous paracetamol every eight hours. Patients were also able to self administer tramadol, another opioid pain medication, by pressing a control button.

Patients With Low Vitamin D Needed More Opioids

Pain levels were recorded immediately after surgery and again at 6, 12, 18, and 24 hours later. Researchers also tracked nausea, vomiting, sedation levels, and length of hospital stay.

Patients with vitamin D deficiency were three times more likely to experience moderate to severe pain during the first 24 hours after surgery compared with patients who had adequate vitamin D levels.

Researchers noted that none of the patients in either group reported severe pain of 7 or higher on the standard 0 to 10 pain scale. The difference was entirely related to a higher number of patients experiencing moderate pain levels between 4 and 6.

The vitamin D deficient group also required more opioid medication. On average, these patients received 8 μg more fentanyl during surgery, which researchers described as a modest increase.

However, after surgery, the difference became much larger. Patients with low vitamin D used an average of 112mg more tramadol than those with sufficient vitamin D levels. The medication was patient controlled, with doses capped at 50mg per hour.

Vitamin D and Recovery Complications

Opioid medications can lead to side effects such as nausea, vomiting, drowsiness, and confusion. They also carry risks of dependence and addiction.

The study found postoperative nausea occurred more often among patients with vitamin D deficiency. Vomiting was only reported in the deficient group, although researchers said the difference was too small to be considered statistically significant.

The researchers acknowledged several limitations. Because the study was observational and conducted at a single medical center, it cannot prove that low vitamin D directly caused the increase in pain. The team also did not measure inflammatory markers that might explain how vitamin D influences pain. In addition, information about anxiety, depression, cancer stage, previous treatments, and sleep problems before surgery was not collected.

Even with those limitations, the researchers concluded, "Vitamin D deficiency is associated with a higher occurrence of moderate to severe postoperative pain and increased opioid consumption in patients undergoing unilateral modified radical mastectomy."

They added, "Preoperative vitamin D supplementation in breast cancer patients with vitamin D levels below 30 nmol/L may have a role in modulating postoperative pain.

https://rapm.bmj.com/content/early/2026/05/04/rapm-2025-107495

https://en.wikipedia.org/wiki/Vitamin_D

Scientists discover strange link between vitamin D and pain | ScienceDaily

Vitamin D Deficiency Linked to Fatigue, Studies Show

In continuation of my update on Vitamin D

Prevalence and Link to Fatigue

Approximately 40% to 75% of the teen and adult population in the United States is deficient in vitamin D, according to Raymond Francis in “The Great American Health Hoax.” ^[1] Low energy and occasional fatigue are commonly reported among individuals with low vitamin D status, according to a report on the silent epidemic of nutrient deficiencies. ^[2] The scale of the problem is vast, with estimates suggesting that nearly half of all adults may have insufficient levels, the report stated.

Vitamin D deficiency is not confined to a single demographic. Factors such as limited sun exposure, darker skin pigmentation, and indoor lifestyles contribute to widespread insufficiency, researchers said. The link between low vitamin D and fatigue has been documented in multiple studies, though many individuals remain unaware of their own deficiency status.

Mechanism: Vitamin D and Cellular Energy

Vitamin D supports mitochondrial function, which is responsible for cellular energy production, according to research cited in an article on fatigue and mitochondria. ^[3] The mitochondria act as the powerhouses of the cell, generating adenosine triphosphate (ATP) from nutrients. A deficiency may disrupt mitochondrial efficiency, contributing to feelings of lethargy, experts said. ^[4]

The role of mitochondria in energy production is central to understanding why vitamin D insufficiency can lead to persistent tiredness. As noted in the book “Dissolving Illusions,” proper mitochondrial metabolism is essential for normal cellular function, and any disruption can manifest as weakness or apathy. ^[5] Although that text focuses on vitamin C, the principle applies broadly to nutrients that support mitochondrial health, including vitamin D.

Supporting Studies

Multiple studies have reported a connection between low vitamin D levels and fatigue. A 2016 study of 200 female nurses in Iran found that low vitamin D levels accounted for 13% to 18% of reported prolonged tiredness, according to a review of nutrient deficiencies. ^[2] A 2019 study published in Nutrients similarly found that older adults with occasional fatigue had a significantly worse vitamin D status than those without fatigue, the review added. ^[2]

Other research has reinforced these findings. In a broader analysis, researchers noted that individuals frequently reporting low energy were more likely to have suboptimal vitamin D levels compared to their peers, according to an article on fatigue and mitochondrial function. ^[4] The consistency of the association across different populations suggests a robust relationship, though causation requires further investigation, scientists said.

Other Health Impacts

Beyond fatigue, vitamin D deficiency has been linked to several other health issues. Vitamin D directly modulates the body’s innate and adaptive immune responses, according to a review of the critical role of vitamin D in immune function. ^[6] Immune cells require adequate vitamin D to respond efficiently to threats, the review stated. Low levels have also been associated with increased susceptibility to infections and longer recovery times.

Vitamin D also influences bone health and cellular aging. Raymond Francis wrote that vitamin D is essential for calcium metabolism, supports bone health, helps control blood sugar, and protects against cancer. ^[1] The nutrient significantly increases the production of telomerase, an enzyme that repairs telomeres and slows aging, according to the same source. ^[1] These wide-ranging effects underscore the importance of maintaining optimal levels.

Solutions: Increasing Vitamin D Levels

Optimal vitamin D levels are considered to be above 50 nanograms per milliliter, and supplementation with 5,000 IU daily is recommended by some nutritionists, according to an interview on health testing and supplementation. ^[7] At-home blood tests can help individuals assess their current levels, the interview stated. ^[7] Testing allows for personalized dosing rather than generic recommendations.

The safety of higher vitamin D doses has been affirmed by recent reassessments. A news report noted that a “schoolboy error” in earlier guidelines led to overly cautious upper limits, and the Academy of Medicine has since acknowledged that higher intakes are not toxic for most people. ^[8] Dietary sources such as fatty fish, egg yolks, and fortified foods can also contribute, though supplementation is often the most reliable way to correct a deficiency, experts said.

Conclusion

Individuals experiencing unexplained fatigue may consider testing their vitamin D levels, clinicians advised. ^[7] Supplementation and dietary changes can help restore levels to the optimal range, though consulting a healthcare provider is recommended before starting any regimen, according to the interview. ^[7]

The evidence linking vitamin D deficiency to fatigue is supported by prevalence data, mechanistic studies, and clinical observations. Given the high rates of insufficiency in the general population, testing and appropriate supplementation offer a straightforward strategy for addressing a common but often overlooked contributor to low energy, researchers concluded.

https://en.wikipedia.org/wiki/Vitamin_D

Vitamin D Deficiency Linked to Fatigue, Studies Show 

Taking vitamin D with quetiapine can help avoid new-onset diabetes risk

In continuation of my update on quetiapine

Atypical antipsychotics, though effective for treating disorders like schizophrenia, bipolar disorder, and depression, gives patients a heightened risk of developing new-onset diabetes. A new data mining study, however, has found a way to relieve this side effect. The study, published in Scientific Reports, shows that taking vitamin D ameliorates the risk of developing new-onset diabetes from atypical antipsychotics like quetiapine.

 quetiapine.

The consequences of developing diabetes from taking antipsychotics are dire, as they occasionally cause life-threatening conditions and sometimes even death.

Members of Shuji Kaneko's lab at Kyoto University looked for potential antidotes on the US FDA's Adverse Event Reporting (FAERS) system, which is the largest database of self-reported adverse side effects. "We found that patients who had coincidentally been prescribed vitamin D with quetiapine were less likely to have hyperglycaemia," says Kaneko. "It's unusual for vitamin D to be prescribed with quetiapine because it is typically prescribed to treat osteoporosis; in fact, there were only 1232 cases in the world where vitamin D was prescribed with quetiapine. Data mining proved helpful in locating these cases."

The team confirmed this finding with further tests on mice; the group of mice that was fed vitamin D along with quetiapine had significantly lower levels of blood sugar than those that took only quetiapine.

"Interestingly, vitamin D on its own doesn't lower diabetes risk, but it certainly defends against the insulin-lowering effects of quetiapine," elaborates lead author Takuya Nagashima. "We clarified the molecular mechanisms of how quetiapine causes hyperglycaemia using datasets in a genomics data repository. Through this we found that quetiapine reduces the amount of a key enzyme called PI3K that gets produced. Vitamin D stops quetiapine from lowering PI3K production."

"Databases like FAERS aren't just for making drug regulations; they have so much potential for side-effect relief using pre-existing drugs," says Kaneko. "There's a lot we can hope for from reverse translational research like this. "

Ref : http://www.kyoto-u.ac.jp/en/research/research_results/2016/160523_2.html