by Marion Nestle

Currently browsing posts about: Vitamin D

Jan 30 2023

Industry-funded research: Vitamin D and Covid-19

I was interested to come across this paper: Conflict of Interests in the Scientific Production on Vitamin D and COVID-19: A Scoping Review.   Front Public Health. 2022 Jul 11;10:821740.   doi: 10.3389/fpubh.2022.821740. eCollection 2022.

Results and conclusions: 

  • Studies were funded by companies in the diagnostics, pharmaceutical and food sectors.
  • Conclusions favorable to vitamin D supplementation were more prevalent in papers where COI was identified (9/13, 69.2%) than among papers where COI was not found (4/16, 25.0%).
  • Omissions of disclosure of COI, funding source, and sponsor functions were observed.
  • The identification of possible corporate political activities in scientific papers about vitamin D published during the COVID-19 pandemic signals a need for greater transparency and guideline development on the prevention of COI in scientific production.

Comment:  Not many studies look at disclosure issues this closely.  This is a welcome addition to the genre.  It reminds me of this especially entertaining report: “COVID-19 and misinformation: how an infodemic fuelled the prominence of vitamin D.”  Papers on vitamin D and COVID-19, it seems, are not only influenced by corporate interests; they are also occasionally fraudulent, if viral.

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Oct 14 2021

The latest in weird waters

I haven’t said much about unusual bottled waters since 2018 when I wrote about bottled ocean water.

2018 was also when I went on The Daily Show to be interviewed by Desi Lydic as the straitperson for her deep dive into “raw water” (surely, the funniest thing I’ve ever done).

Well, you can’t make up these things.

  • Karma Water launches CBD Water:  Karma Water – a US brand which Constellation Brands has a minority stake in – has launched Karma CBD Water: the first such beverage in its wellness and probiotic waters beverage portfolio…. Read more
  • Shine Water with Vitamin D: That this is about marketing more than health is evident from at least one review: “The brand messaging is where things go a little off track, slamming you with callouts and copy, trying to establish credibility for the drink’s functionality. These include a large green vitamin D callout, a Vitamin D Council “approved” logo, a “developed by physicians” logo, two mentions of their charitable intentions (5 percent of profits — a problem in that most startup beverage companies have zero or minimal profits for a while).
  • Psychedelic Water: A friend who prefers to remain anonymous forwarded an e-mail from this company: “We would love to arrange an interview with you and the team of disruptors behind the launch of the first legal psychedelic, mild mood-boosting, hangover-free fun…Psychedelics have been touted in the media lately for the extreme benefits they have on mental health, depression, happiness, mood-stabilizing, and overall general well-being. Psychedelic Water works because it is the world’s first legal psychedelic blend of kava root, damiana leaf, and green tea A leaf extract for an experience like no other.

My only comment:  Really, there are better ways to get CBD, vitamin D, or even high if that’s what you are looking for.  Me?  I’m sticking to plain, ordinary drinking water, sometimes fizzed up a bit.

Mar 1 2021

Industry-funded study of the week: vitamin D supplements

The Study:  Maaike J. Bruins and Ulla Létinois. Adequate Vitamin D Intake Cannot Be Achieved within Carbon Emission Limits Unless Food Is Fortified: A Simulation Study.  Nutrients 202113(2), 592; https://doi.org/10.3390/nu13020592

Conclusion: The present study shows that adequate intakes for vitamin D cannot be achieved with the current diet alone within realistic calorie and carbon emission limits, and additional vitamin D sources are needed to overcome the shortfalls. Universal fortification along with small dietary shifts represents an approach to improve the vitamin D status of the general population, at a high acceptability without affecting the carbon footprint.

Conflicts of Interest: M.J.B. and U.L. are employed by DSM Nutritional Products, a manufacturer of nutritional ingredients.

Comment: Study after study shows that vitamin D supplements do not make healthy people healthier, but the idea persists and supplement companies take advantage of faith in these products.  Well, there isn’t much evidence for harm either, but sunshine on skin is a better source by far.

OK.  I know there’s a big controversy about this.

Here’s a study that shows benefits for patients with COVID; supplements were associated with keeping people out of intensive care.  One of its authors has financial ties to supplement companies, but the study has been criticized on other grounds as has a member of the British Parliament who thinks it provides evidence for supplementing everyone.

And here’s an independently funded study in JAMA shows that vitamin D to have no effect on patients hospitalized with Covid-19.

This one, comes with an editorial.

Given the lack of highly effective therapies against COVID-19, except perhaps for corticosteroids, it is important to remain open-minded to emerging results from rigorously conducted studies of vitamin D (despite smaller sample sizes and important limitations of some studies). However, taken together with existing randomized clinical trials of vitamin D administration in hospitalized patients with respiratory infection and critical illness, the results reported by Murai et al12 do not support routine administration of vitamin D in hospitalized patients with moderate to severe COVID-19.

Fortunately, vitamin D supplements are unlikely to be harmful unless taken in very large doses.

Sunshine, anyone?

Jan 21 2021

Vitamin D and coronavirus: more on the ongoing saga

Vitamin D is such a hot topic for its purported role in preventing or treating coronavirus infections that I seem to have written about it four previous times.  These are here, here, here, and here.

Now, a group of 120 scientists has called on world governments to get their populations to increases vitamin D consumption to 2000 to 4000 units per day, five to ten times higher than current recommendations.  Their letter is here.

This is especially interesting because nutrition and health societies in the UK  advise quite the opposite: no change in the usual recommendation for vitamin D intake (400 units/day).  Their report says (my emphasis):

  • Do not offer a vitamin D supplement to people solely to prevent COVID-19, except as part of a clinical trial.
  • Do not offer a vitamin D supplement to people solely to treat COVID-19, except as part of a clinical trial.

I’m always interested to see what ConscienHealth has to say about such things.

The passion of the vitamin D fan club is striking. However, neither passion nor speculation should be a substitute for facts. Right now, the facts tell us that the reason to take a vitamin D supplement is to protect our muscles and bones. Any thought that it will help with COVID-19 is speculation, and taking too much would be quite unwise.

My sentiments precisely.

Oct 27 2020

Vitamin D and Coronavirus: Panacea or sign of good health?

Evidence is pouring in that people with adequate vitamin D status seem to be better protected against harmful effects of Covid-19.

This is not surprising; people who practice healthful lifestyles—eating well, being active, getting out in the fresh air, maintaining a healthy weight, not smoking, not drinking too much—generally survive this infection more easily.

Vitamin D, I must remind you, is not really a vitamin.  It is a hormone induced by the effects of sunlight on skin.

Sunlight is by far the most effective way to get it.   Foods provide much less.

As for supplements, it’s hard to say.  They are under investigation.

I’ve been collecting items:

  • An account of a clinical trial in Italy published in Medium: “Among the 26 hospitalized people who received standard care alone, fully half went on to the intensive care unit (ICU) because their disease had worsened. Two of them died. But among the 50 people who received the vitamin D treatment on top of standard care, only one person ended up in the ICU. None died.”  The study itself concludes: “…administration of a high dose of Calcifediol or 25-hydroxyvitamin D…significantly reduced the need for ICU treatment of patients requiring hospitalization due to proven COVID-19. Calcifediol seems to be able to reduce severity of the disease, but larger trials with groups properly matched will be required to show a definitive answer.”
  • Medium’s discussion of what is known about Vitamin D supplements and Covid-19: “If we ask the question “Does vitamin D prevent/treat COVID-19?” the only real answer is “How could you possibly know?””
  • Consumer Reports on whether you should be taking vitamin D supplements: its not-particularly-helpful conclusion: “Ultimately, whether to get tested or take a supplement and how to do it comes down to having a discussion with your doctor.”

As always with supplements, a market is involved.  This one is not trivial, even in the UK.

An obesity newsletter I subscribe to—Obesity and Energetics Offerings—provides items suggesting that conflicts of interest may be involved.

  • Vitamin D deficiency linked to 54% higher SARS-CoV-2 positivity rate: Study: The associations between vitamin D status and COVID-19 risk continue to strengthen, with new data from Quest Diagnostics and Boston University indicating that people with deficiency in the sunshine vitamin may have a significantly higher positivity rate for SARS-CoV-2, the coronavirus that causes COVID-19.
  • The study in question, Evidence That Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths, reports conflicted interests: “W.B.G receives funding from Bio-Tech Pharmacal, Inc. (Fayetteville, AR). H.L. sells vitamin D supplements. GrassrootsHealth works with various supplement suppliers to test the efficacy of their products in various custom projects. These suppliers may be listed as sponsors of GrassrootsHealth.”   Basically, it’s industry-funded.
  • One letter in response to the study points out that “the efficacy of high-dose supplementation of vitamin D3 in reducing risk of COVID-19 infection is mere extrapolation of currently available evidence, which is often conflicting, on the effectiveness of vitamin D3 in reducing risk of other respiratory tract infections.”
  • To this, the authors have a lengthy rebuttal.

My bottom line at the moment: the science is still unfolding.  What to do while waiting for further research?  I like these Considerations for Obesity, Vitamin D, and Physical Activity Amid the COVID-19 Pandemic:

Until further breakthroughs emerge, we should remember that modifiable lifestyle factors such as diet and physical activity should not be marginalized. Decades of empirical evidence have supported both as key factors promoting health and wellness. In times of crisis, whether it be real or perceived, there is something to be said about the benefits of empowering people to actively preserve their own health.

Get outside, move around, expose some skin to sunlight.  Even in winter.

 

May 27 2020

What’s the story on Vitamin D

Yesterday, I wrote about current research suggesting that higher levels of blood Vitamin D [actually, 25-hydroxycholecalciferol, or 25(OH)D] help to protect against Covid-19.

To understand concerns that this evidence may not be totally convincing, it’s useful to know the basics about this “vitamin,” which I put in quotes because its active form is a hormone that helps govern calcium balance.  Here’s how it works.

  • Sunlight acts on a form of cholesterol in skin (7-dehydrocholesterol) to covert it to cholecalciferol, the chemical name for vitamin D3.
  • Vitamin D3 goes to the liver where an enzyme converts it to 25 (OH)D.
  • 25(OH)D goes to the kidney where an enzyme converts it to 1,25-dihydroxycholecalciferol (a.k.a. 1,25-dihydroxyvitamin D), the active hormone.

If you eat foods containing vitamin D3 (fish and meat, which have it in very small amounts, or fortified milk) or vitamin D2 from plants, yeast, or supplements, these travel in the blood to the liver where they undergo the same metabolic steps.

This means that there are three sources.

  • Sunlight on skin—this produces thousands of IU (International Units)
  • Food—is low in this vitamin
  • Supplements—vary, but high doses are not recommended by most health authorities; they may induce hyper-immune responses (not a good idea)

The commonly recommended daily dose of vitamin D is 400-600 IU.

Sunlight on skin is by far the best way to get your vitamin D hormone.

Sensible sun exposure, especially between the hours of 10:00 am and 3:00 pm produces vitamin D in the skin that may last twice as long in the blood compared with ingested vitamin D.If sun exposure produces slight pinkness, the amount of vitamin D produced in response to exposure of the full body is equivalent to ingesting 10,000-25,000 IU.

 In the UK, a study showed that 13 minutes of midday sunlight exposure during summer, just three times per week, maintains healthy levels in white adults ; other studies have shown 30 minutes of midday summer sun exposure in Oslo to be equivalent to consuming 10,000–20,000 IU of vitamin D.

How does all this relate to Covid-19?

So far, we do not have studies of vitamin D supplements in patients with Covid-19 or longer term prospective trials.  These will undoubtedly come.

While waiting for those results, enjoy the sunshine!

May 26 2020

Vitamin D and Coronavirus? Will it help?

In the past few weeks, several studies have appeared linking low levels of the vitamin D intermediate, 25-hydroxycholecalciferol [25(OH)D] to Covid-19 severity.

Previous studies have noted that vitamin D deficiency may be a biomarker of sepsis risk, and giving supplements helps to protect people from acute respiratory infections.

Supplements?

The supplement marketer Wileys Finest says

Did you know there is a special role for vitamin D in our immune cells? Our immune cells use vitamin D to function normally. That’s why experts recommend supplementing with 2,000 IU per day (50 mcg) to support healthy immune function.1,2  P.S. Vitamin D3 is the better choice!

It cites two additional studies:

But wait!

COVID-19: Internet ‘rife with misinformation’ about Vitamin D, say scientists.  Reports arguing high dose Vitamin D supplementation could treat COVID-19 are based on speculation and are a risk to public health, warns a team of scientists from across the globe…. Read more.

This article refers to Vitamin D and SARS-CoV-2 virus/COVID-19 disease, by Martin Kohlmeier and colleagues.  These scientists summarize the situation succinctly (rearranged for readability).

(1) Vitamin D is essential for good health.

(2) Many people, particularly those living in northern latitudes (such as the UK, Ireland, Northern Europe, Canada and the northern parts of the USA, northern India and China), have poor vitamin D status, especially in winter or if confined indoors.

(3) Low vitamin D status may be exacerbated during this COVID-19 crisis (eg, due to indoor living and hence reduced sun exposure), and anyone who is self-isolating with limited access to sunlight is advised to take a vitamin D supplement according to their government’s recommendations for the general population (ie, 400 IU/day for the UK7 and 600 IU/day for the USA (800 IU for >70 years)) and the European Union (EU).

(4) There is no strong scientific evidence to show that very high intakes (ie, mega supplements) of vitamin D will be beneficial in preventing or treating COVID-19.

(5) There are evidenced health risks with excessive vitamin D intakes especially for those with other health issues such as a reduced kidney function.

This seems like sensible advice.

As readers of this blog know, I am not a fan of supplements, particularly in high doses, mainly because there is so little evidence that supplements do anything to make healthy people healthier.  There is also some evidence that they could be harmful, especially those that are fat-soluble, as is vitamin D.

I am particularly skeptical of the benefits of Vitamin D:

  • Its best source by far is from the action of sunlight on skin.
  • It is not a vitamin; it is a hormone (widespread hormone replacement therapy does not seem like a good idea).
  • It is unclear whether 25 (OH)D is the best measure of hormone status (it is just the easiest one to do).
  • More research on immune effects is needed.

In the meantime, what to do?

It’s summer in the Northern Hemisphere.  Get outside!

Tomorrow: I will explain more about why the effects of Vitamin D are so hard to figure out.

Apr 16 2020

Watch out for Coronavirus frauds and unproven promises

Frauds and fraudulent information are so prevalent that the FDA says what it’s doing about them on its Coronavirus web page.

My email inbox is deluged with marketers claiming that their products boost immune systems in general, and protect against Coronavirus in particular.  Often, they cite evidence but this is highly selective and sometimes based on studies paid for by their sponsors.

The bottom line on keeping immune systems healthy?  Eat a healthful diet, don’t gain excess weight, and get plenty of physical activity.  OK, good luck doing that while you are under lockdown, but you can give it a good try.

Here are some of the items that have ended up in my inbox.

Despite FDA pronouncements, industry coalition action, the coronavirus claims warning letters keep coming:  The US Food and Drug Administration has issued an additional six warning letters in recent days on coronavirus claims. The letters coincide with an industry coalition raising a red flag on the growing flood of such claims on dietary supplement-type products….Read more

Unproven COVID-19 health claims: China’s crackdown on ads for oral sprays, probiotics and anti-hangover tea: The Chinese authorities have named and shamed a string of fake advertisement, mostly surrounding unproven COVID-19 health claims.

Consumers warned of sports nutrition products making coronavirus claimsThe European Specialist Sports Nutrition Alliance (ESSNA) has warned consumers of the increase in companies and individuals making unfounded claims in light of the current coronavirus situation….Read more

Cocoa and the coronavirus: can it boost the immune system?  Cacao beans have been consumed by humans for over 3,000 years and the ingredient is well-known for its wide range of health benefits, recent research suggests it can provide stronger protection against influenza virus infection…. Watch now [but watch critically.  If you even give this a moment’s thought….]

 

CRN UK highlights why essential nutrients have never been more essential:  The ongoing threat of coronavirus could increase the potential for deficiencies in key micronutrients supporting the immune system, according to The Council for Responsible Nutrition UK (CRN UK). Read more  [How about eating a healthy diet and getting plenty of exercise?].

Could vitamin D play a role in coronavirus resistance? Research thinks so:  Vitamin D supplements may aid in the resistance of respiratory infections such as the coronavirus or limit the severity of the illness in those infected, according to researchers. Read more.  [And what kind of research are we talking about here?  Some of it is industry-funded, as this example demonstrates (thanks to Claudia Santos for sending)].