Tag: vitamin D

Wealth Divide, not Vitamin D, Explains Differing MS Rates

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Differences in vitamin D exposure have been thought to explain why people who live farther from the equator are more likely to develop multiple sclerosis (MS). But countries farther from the equator are also more likely to be wealthier. A new analysis published in Neurology shows that the amount a country spends on health care may help explain this relationship between MS and latitude.

According to study author Deanna Saylor, MD, MHS, the results suggest that MS rates may be greatly underestimated in low-income countries with lower health care spending, which means that people have less access to neurologists who have the expertise to diagnose MS and MRI scanners that are needed to make the diagnosis.

Researchers analysed data from scientific studies and databases to determine current rates of MS in 203 countries and territories. Countries were then grouped into world regions and by income levels.

Rates of MS varied by region and income level. For example, in high-income countries an average of 46 of every 100 000 people had MS, compared to 10 people per 100 000 in low-income countries. Health care spending per capita was $2805 for high-income countries, compared to $45 in low-income countries.

For each location, researchers examined gross domestic product per capita, current health expenditure per capita, income levels, the availability of brain scans to diagnose MS, the number of neurologists per capita and universal health care. They also reviewed lifestyle factors such as obesity and tobacco use.

Once the researchers adjusted the data for other factors that could affect the risk of MS, such as age and sex, they found that health care spending and latitude were strongly associated with MS rates. The research showed that, with every increase of one standard deviation in health expenditure per capita, a country’s MS prevalence increased by 0.49. Alternatively, with every increase of one standard deviation in latitude, a country’s MS prevalence increased by 0.65.

Researchers also found that health care spending explained some, but not all, of the link between latitude and MS. After adjusting for other factors, the link between latitude and MS decreased by more than 20% when health care expenditure per capita was considered.

The availability of universal health care was associated with rates of MS in all world regions, except Southeast Asia, with universal health care tied to higher rates of MS.

In high-income countries, rates of MS were linked to most factors, including gross domestic product per capita, current health expenditure per capita, and the number of neurologists, but not tobacco use and obesity or the number of MRI units per capita. However, in low-income countries, there were no associations with any of these factors, which may be explained by a lack of significant variation in data from these countries, Saylor said.

According to Dr Saylor, the finding that current health expenditure per capita was very strongly linked with national rates of MS further supports the hypothesis that greater investment in health care leads to more robust reporting of rates of MS. She also said the minimal links between rates of MS and lifestyle factors such as tobacco use and obesity run counter to prior assumptions that lifestyle and consumption behaviours explain the large portions of regional differences in reported rates of MS.

Dr Saylor said strategies are urgently needed for the accurate assessment of the burden of MS in low-income countries, and these lower reported MS can obscure the need for training and funding regarding MS.

A limitation of the study is that different data sources may have collected information during different time periods or used different methods, which could affect the accuracy of estimates.

Source: American Academy of Neurology

Chronic Inflammation Link to Low Vitamin D Explains Some Controversies

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New genetic research shows a direct link between low vitamin D levels and high levels of inflammation, providing an important biomarker to identify people at higher risk of or severity of chronic illnesses with an inflammatory component, such as type 2 diabetes. The findings, published in the International Journal of Epidemiology, also helps to settle some of the controversies surrounding the ‘sunshine vitamin’.

The study drew on genetic data for 294 970 participants in the UK Biobank, using Mendelian randomisation to show the association between vitamin D and C-reactive protein levels, an indicator of inflammation.

University of South Australia’s Dr Ang Zhou, the study’s lead researcher, said that the findings suggest that boosting vitamin D in people with a deficiency may reduce chronic inflammation.

“This study examined vitamin D and C-reactive proteins and found a one-way relationship between low levels of vitamin D and high levels of C-reactive protein, expressed as inflammation.

“Boosting vitamin D in people with deficiencies may reduce chronic inflammation, helping them avoid a number of related diseases.”

The study also raises the possibility that having adequate vitamin D concentrations may mitigate complications arising from obesity and reduce the risk or severity of chronic illnesses with an inflammatory component, such as CVDs, diabetes, and autoimmune diseases.

Senior investigator and Director of UniSA’s Australian Centre for Precision Health, Professor Elina Hyppönen, said that these results offer an explanation for some of the controversies in reported associations with vitamin D.

“We have repeatedly seen evidence for health benefits for increasing vitamin D concentrations in individuals with very low levels, while for others, there appears to be little to no benefit.” Prof Hyppönen said.

“These findings highlight the importance of avoiding clinical vitamin D deficiency, and provide further evidence for the wide-ranging effects of hormonal vitamin D.”

Source: University of South Australia

Vitamin D ‘Overdoses’ are Possible – and Dangerous

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Doctors have warned that it it is possible to ‘overdose’ on Vitamin D, with harmful effects, after they treated a man hospitalised for excessive Vitamin D intake, a case which was detailed in BMJ Case Reports.

They further stress that ‘hypervitaminosis D’ is on the increase, and linked to a wide range of potentially serious health issues.

The case concerns a middle-aged man who was referred to hospital by his family GP after complaining of recurrent vomiting, nausea, abdominal pain, leg cramps, tinnitus, dry mouth, increased thirst, diarrhoea, and weight loss (12.7 kg). 

The patient had been experiencing these symptoms had for almost three months, which had started around one month after he began an intensive vitamin supplement regimen on the advice of a nutritional therapist.

The man had had a number of health issues, including tuberculosis; a left vestibular schwannoma, resulting in deafness in that ear, hydrocephalus; bacterial meningitis; and chronic sinusitis.  

He had been taking high doses of more than 20 over the counter supplements every day containing: vitamin D 50 000mg – the daily requirement is 600mg or 400IU; vitamin K2 100mg (daily requirement 100–300 μg); vitamin C, vitamin B9 (folate) 1000mg (daily requirement 400 μg); vitamin B2 (riboflavin), vitamin B6, omega-3 2000mg twice daily (daily requirement 200–500 mg), plus several other vitamin, mineral, nutrient, and probiotic supplements.

Once he developed symptoms, he stopped taking his daily supplement cocktail, but his symptoms didn’t go away.

Blood test results from his family doctor revealed that he had very high levels of calcium and slightly raised levels of magnesium. And his vitamin D level was seven times over the level required for sufficiency.

The tests also indicated acute kidney injury. The results of various x-rays and scans to check for cancer were normal. 

The man was hospitalised for 8 days, during which time he was given intravenous fluids to flush out his system and treated with bisphosphonates – ordinarily used to treat osteoporosis or hypercalcaemia.

Two months post-discharge, his calcium level had returned to normal, but his vitamin D level was still abnormally high.

“Globally, there is a growing trend of hypervitaminosis D, a clinical condition characterised by elevated serum vitamin D3 levels,” with women, children and surgical patients most likely to be affected, the authors noted. 

Recommended vitamin D levels can be obtained through diet, sunlight exposure to sunlight, and supplements.

“Given its slow turnover (half-life of approximately two months), during which vitamin D toxicity develops, symptoms can last for several weeks,” the authors warned.

Hypervitaminosis D has many and varied symptoms, they point out, and are mostly caused by hypercalcaemia. They include drowsiness, confusion, apathy, psychosis, depression, stupor, coma, anorexia, abdominal pain, vomiting, constipation, peptic ulcers, pancreatitis, hypertension, abnormal heart rhythm, and kidney abnormalities, including renal failure. 

Other associated features, such as keratopathy (inflammatory eye disease), joint stiffness (arthralgia), and hearing loss or deafness, have also been reported, they add.

This is just one case, and while hypervitaminosis D is on the rise, it is still relatively uncommon, the authors cautioned.

Nevertheless, complementary therapy, including the use of dietary supplements, is popular, and people may not realise that it’s possible to overdose on vitamin D, or the potential consequences of doing so, they say.

“This case report further highlights the potential toxicity of supplements that are largely considered safe until taken in unsafe amounts or in unsafe combinations,” they concluded.

Source: The BMJ

Vitamin D Doesn’t Prevent the Development of Type 2 Diabetes

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Daily vitamin D supplements do not seem to prevent the development of type 2 diabetes in people already at high risk of the condition, according to a Japanese trial published by The BMJ.

While no clinically meaningful effect was seen in high risk adults, the results hinted that there may be a benefit for people with insufficient insulin secretion.

Type 2 diabetes affects around 480 million people worldwide, and is predicted to increase to 700 million by 2045. Another half a billion people have impaired glucose tolerance or pre-diabetes (higher than normal blood sugar levels that, if left untreated, can develop into type 2 diabetes).

Weight loss and exercise can lower the risk of progression to type 2 diabetes, but are difficult to sustain, so new strategies are needed to tackle the problem.

An association between vitamin D deficiency and an increased risk of future diabetes has been shown in some studies, but trials of vitamin D supplements for preventing type 2 diabetes show inconsistent results.

To address this knowledge gap, researchers therefore set out to assess whether eldecalcitol (an active form of vitamin D used to treat osteoporosis in Japan) could reduce the risk of developing type 2 diabetes among people with impaired glucose tolerance.

The study involved 1256 Japanese adults with impaired glucose tolerance with an average age of 61 years; 46% were women, and 59% had a family history of type 2 diabetes.

Participants were randomly assigned to receive either a standard daily dose of eldecalcitol (630 participants) or placebo (626 participants) and were assessed for diabetes every three months over a three-year follow-up period.

During this period, the researchers found no meaningful differences between groups in those who developed diabetes (12.5% in the eldecalcitol group and 14% in the placebo group) or whose blood sugar levels returned to normal (23% in the eldecalcitol group and 20% in the placebo group).

However, after adjusting for 11 potentially influential factors, including age, sex, blood pressure, body mass index, and family history of diabetes, the results suggested that eldecalcitol might prevent type 2 diabetes in pre-diabetic patients with insufficient insulin secretion. But this finding remains unclear and the researchers say further work is needed before any firm conclusions can be made.

They did, however, find a significant increase in both lower back and hip bone mineral densities among those taking eldecalcitol compared with placebo.

No significant difference in serious adverse events was seen between the two groups.

The researchers acknowledge some uncertainties, such as whether the dose of eldecalcitol used was appropriate for preventing diabetes, and whether the results apply to all ethnicities. Nevertheless, this was a large trial with regular follow-up and high adherence to treatment, suggesting that the findings are robust.

As such, they say: “Although treatment with eldecalcitol did not significantly reduce the incidence of diabetes among people with pre-diabetes, the results suggested the potential for a beneficial effect of eldecalcitol on people with insufficient insulin secretion.” And they call for further research to determine whether vitamin D is beneficial to people with pre-diabetes.

This new trial was well conducted and results are consistent with two other recent trials, said Tatiana Christides at Queen Mary University of London in a linked editorial.

However, several questions remain, she writes, including whether vitamin D supplementation may be more effective for particular populations, and whether longer duration of treatment or younger age at initiation might be more beneficial.

Until further data are available from high quality randomized trials, she suggests healthcare professionals “should continue to discuss with patients the musculoskeletal health benefits of vitamin D and support them to achieve and maintain lifestyle changes that, although challenging to sustain, are known to decrease development of type 2 diabetes.”

Source: News-Medical.Net

Study Finds That Vitamin D3 Has a Greater Health Benefit Than D2

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A new study has found that vitamin D2 and D3 have significant differences in effect, with vitamin D2 having a questionable impact on human health. However, the study found that vitamin D3 (the ‘sunshine vitamin’) could balance people’s immune systems and help strengthen defences against viral infections.

In a study published in Frontiers in Immunology, researchers investigated the impact of vitamin D supplements, D2 and D3, taken daily over a 12-week period on the activity of genes in people’s blood.

Contrary to widely held views, the research team discovered that both types of vitamin D did not have the same effect, rather they found evidence that vitamin D3 influences the immune system in a way that could fortify the body against viral and bacterial diseases.

Professor Colin Smith, lead-author of the study from the University of Surrey, who began this work while at the University of Brighton, said: “We have shown that vitamin D3 appears to stimulate the type I interferon signalling system in the body – a key part of the immune system that provides a first line of defence against bacteria and viruses. Thus, a healthy vitamin D3 status may help prevent viruses and bacteria from gaining a foothold in the body.

“Our study suggests that it is important that people take a vitamin D3 supplement, or suitably fortified foods, especially in the winter months.”

Few natural foods contain Vitamin D, although some such as bread and yoghurt may be fortified with it. Vitamin D3 is produced naturally in the skin from exposure to sunlight or artificial ultraviolet UVB light, while some plants and fungi produce vitamin D2.

Many people have insufficient levels of vitamin D3 because they live in locations where sunlight is limited in the winter, like the UK. Sunlight exposure has also been limited by the COVID pandemic as people spend more time in their homes.

Professor Susan Lanham-New, co-author of the study and Head of the Department of Nutritional Sciences at the University of Surrey, said: “While we found that vitamin D2 and vitamin D3 do not have the same effect on gene activity within humans, the lack of impact we found when looking at vitamin D2 means that a larger study is urgently required to clarify the differences in the effects. However, these results show that vitamin D3 should be the favoured form for fortified foods and supplements.”

Source: University of Surrey

Vitamin D Supplements Reduce Autoimmune Disease Risk

A five year-long randomised, placebo-controlled study found that in older adults taking vitamin D supplements, alone or with omega-3 fatty acids, the risk of developing autoimmune disease was reduced.

Autoimmune diseases (AD) such as rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease and psoriasis, are a leading cause of morbidity and mortality as people age. Few effective treatments are available for AD, but some research has hinted that supplements, including vitamin D and omega-3 fatty acids, could have beneficial effects.

In a new study published in the BMJ, investigators from Brigham and Women’s Hospital evaluated whether taking vitamin D and/or omega fatty acid supplements could affect rates of AD. The large-scale vitamin D and Omega-3 Trial (VITAL), a randomised study which followed participants for approximately five years. Taking vitamin D, or vitamin D and omega-3 fatty acids had a significantly lower rate of AD than placebo.

“It is exciting to have these new and positive results for non-toxic vitamins and supplements preventing potentially highly morbid diseases,” said senior author Karen Costenbader, MD, MPH. “This is the first direct evidence we have that daily supplementation may reduce AD incidence, and what looks like a more pronounced effect after two years of supplementation for vitamin D.”

“Now, when my patients, colleagues, or friends ask me which vitamins or supplements I’d recommend they take to reduce risk of autoimmune disease, I have new evidence-based recommendations for women aged 55 years and older and men 50 years and older,” said Dr Costenbader. “I suggest vitamin D 2000 IU a day and marine omega-3 fatty acids (fish oil), 1000 mg a day – the doses used in VITAL.”

VITAL included 25 871 participants, with men aged 50 and older and women aged 55 and older, conducted to investigate whether taking vitamin D3 and/or omega-3 supplements could reduce the risk for developing cancer, heart disease and stroke in people who do not have a prior history of these illnesses. Prior to the launch of VITAL, investigators determined that they would also look at rates of AD among participants, as part of an ancillary study.

Participants answered questionnaires about new diagnoses of diseases, including rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid disease, psoriasis and inflammatory bowel disease, with space to write in all other new onset ADs. Medical records were reviewed to confirm reported diagnoses.

“Autoimmune diseases are common in older adults and negatively affect health and life expectancy. Until now, we have had no proven way of preventing them, and now, for the first time, we do,” said first author Jill Hahn, ScD, post-doctoral fellow at the Brigham.

Among patients randomised to vitamin D, 123 participants in the treatment group and 155 in the placebo group were diagnosed with confirmed AD (22 percent reduction). Among those in the fatty acid arm, confirmed AD occurred in 130 participants in the treatment group and 148 in the placebo group. Omega-3 fatty acids alone did not significantly lower incidence of AD, but there was some evidence of a decrease over long periods.

Source: EurekAlert!

Low Vitamin D in Pregnancy Can Raise Autism Risk

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Low maternal vitamin D intake during pregnancy can affect the development of autism in the child along with various other factors, according to a new study from the University of Turku, Finland, and Columbia University, USA.

The study, published in the Biological Psychiatry journal, included 1558 cases of autism spectrum disorder (ASD) and an equal number of matched controls born in Finland between January 1987 and December 2004, followed up until December 2015. 

Maternal vitamin D deficiency during pregnancy was linked to a 44% increased risk of ASD in the offspring, compared to women with sufficient vitamin D. 

The result persisted even when accounting for maternal age, immigration, smoking, psychopathology, substance abuse, the gestational week of blood draw, season of blood collection, and gestational age.

“The results are significant for public health as vitamin D deficiency is readily preventable,” said first author, Professor Andre Sourander from the University of Turku.

In previous work, the researchers had shown that vitamin D deficiency is also associated with increasede ADHD risk in the offspring. The serum samples were collected before the national recommendation for vitamin D supplementation during pregnancy was introduced in Finland. The current recommendation for pregnant women is a daily supplement of 10 micrograms of vitamin D throughout the year.

“Vitamin D deficiency is a major global problem,” Prof Sourander remarked.

Source: University of Turku

Solar Exposure Guidelines Could be Revised

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Previously published solar exposure guidelines for optimal vitamin D synthesis that were based on a study of skin samples may have to be revised. 

A study published in PNAS has tested the optimum ultraviolet radiation (UVR) wavelengths for human skin production of vitamin D in sunlight.

Though UVR from sunlight can cause sunburn and skin cancer, it is the most important source of vitamin D.

Public health advice on sunshine exposure balances its risk and benefit, which is not a simple task because the health outcomes from UVR exposure vary considerably with wavelength within the sun’s UVR spectrum. For example, the sun’s UVR contains less than 5% short wavelength UVB radiation but this is responsible for over 80% of the sunburn response. Each health outcome from solar exposure has its own unique wavelength dependency.

The link between specific UVB wavelengths and vitamin D production was determined more than thirty years ago in ex vivo skin samples. However, the finding is less well established, with doubts on its accuracy which compromise risk/benefit calculations for optimal solar exposure.

Researchers led by the Professor Antony Young from King’s College London measured blood vitamin D levels in 75 healthy young volunteers, before, during, and after partial or full body exposure to five different artificial UVR sources with different amounts of UVB radiation, to gauge the trade-off between solar exposure benefits, which include vitamin D synthesis, versus the risks of sunburn and skin cancer.

The results were compared against predictions from the old ex vivo vitamin D study, finding that it was not an accurate predictor of benefit from UVR exposure.

The authors’ recommendation is a systematic correction of the ex vivo wavelength dependency for vitamin D. The new study means that many risk benefit calculations for solar UVR exposure must be reviewed with a revised version of the wavelength dependency for vitamin D.

“Our study shows that risk versus benefit calculations from solar exposure may need to be re-evaluated. The results from the study are timely because the global technical committee, Commission internationale de l’éclairage, that sets UVR standards will be able to discuss the findings of this paper to re-evaluate the wavelength dependency of vitamin D. Further research from our group will determine the risk/benefit calculations.”

Professor Antony Young, King’s College London

Source: King’s College London

Extra Vitamin D Does not Boost Muscles

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Vitamin D supplementation does not have beneficial effects on muscle function, strength, or mass, according to a new meta-analysis, and may even have detrimental effects on muscle strength in people with normal levels of the vitamin.

Vitamin D deficiency, causes a generalised decrease in bone mineral density, resulting in osteopenia and osteoporosis. In young children who have little mineral in their skeleton, this defect results in a variety of skeletal deformities classically known as rickets. It is also believed to cause muscle weakness; affected children have difficulty in standing and walking, whereas the elderly have increasing sway and more frequent falls,thereby increasing their risk of fracture.

The analysis, which is published in the Journal of Bone and Mineral Research, included 54 trials involving 8747 individuals. Overall, no benefits of vitamin D over placebo were observed for improving muscle health. On the contrary, vitamin D appeared to have detrimental effects in terms of increased time spent performing what’s called the Timed Up and Go test, a decrease in maximum strength at knee flexion, and a tendency towards a reduced score of the Short Physical Performance Battery.

“Care should be taken recommending vitamin D supplementation to improve muscle strength and function in people with normal or only slightly impaired vitamin D status,” said lead author Lise Sofie Bislev, MD, PhD, of Aarhus University Hospital, in Denmark. “We need to study further whether it may benefit muscles in those with severe vitamin D deficiency, however.”

Source: Wiley

Vitamin D Deficiency Shown to Increase COVID Severity and Mortality

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A new study conducted by the Azrieli Faculty of Medicine of Bar-Ilan University and its affiliate Galilee Medical Center (GMC) is one of the first to show that vitamin D deficiency before infection is associated with increased COVID severity and mortality. The study is available on the medRxiv preprint server, awaiting peer review.

Vitamin D has attracted attention in prevention of severe COVID as its levels are known to be related to risks of influenza and respiratory tract infections. It also has direct antiviral effects primarily against enveloped viruses, which include coronaviruses.

Previous studies that examined the link between vitamin D levels and SARS-CoV-2 infection had mixed results. Most measured vitamin D levels once patients were already sick, making interpretation of the results difficult. The new study assessed this correlation using low levels of vitamin D measured prior to infection and also focused on disease severity.

The researchers searched for vitamin D levels measured 14 to 730 days prior to positive PCR tests in the records of individuals admitted between April 2020 and February 2021 to GMC in Nahariya, Israel.

Of 1176 patients admitted, 253 had vitamin D levels recorded prior to COVID infection. Compared to mildly or moderately diseased patients, those with severe or critical COVID disease were more likely to have severe pre-infection vitamin D deficiency with levels less than 20 ng/mL.

“This study can highlight the risks of vitamin D deficiency in terms of COVID-19,” said Dr Amiel Dror, of GMC and the Azrieli Faculty of Medicine of Bar-Ilan University, who led the study. “Vitamin D is often associated with bone health. We’ve shown that it may also play an important role in other disease processes, such as infection.”

Prof Michael Edelstein, of the Azrieli Faculty of Medicine of Bar-Ilan University said, “It is still unclear why certain individuals suffer severe consequences of COVID-19 infection while others don’t. Our finding adds a new dimension to solving this lingering puzzle. In Israel, where vitamin D deficiency is common in certain population groups, this finding is particularly important.”

The authors said that the link between low pre-infection vitamin D levels and severe COVID does not necessarily imply that giving vitamin D to COVID patients will decrease the risk of severe disease. However, it does highlight the need to better manage vitamin D deficiency.

Source: Bar-Ilan University