Debunking the vitamin D fad
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Throughout the pandemic, many unproven miracle COVID-19 “cures” emerged, and vitamin D claims have been one of the most persistent. This is not new for the vitamin. It’s been touted in recent decades as a way to “boost” the immune system, improve overall health, prevent a host of diseases, and allegedly even substitute for vaccines.
But as with many internet-popular health “remedies,” the reality is far less flashy and far more nuanced.
What is vitamin D, and why is it important?
Vitamin D is a nutrient that helps the body absorb calcium, which is essential for bone health. In the sunlight, your skin naturally produces vitamin D that is then stored in fat cells until it is used.
The skin pigment melanin absorbs the UV rays necessary for vitamin D production, meaning that more highly pigmented or darker skin produces less vitamin D than lighter skin with the same amount of sun exposure. Thus, people with darker skin are at higher risk of vitamin D deficiency.
Most of our vitamin D comes from the sun. An additional 10 percent to 20 percent of our vitamin D comes from foods like fatty fish (such as salmon), eggs, and mushrooms. Vitamin D supplements are another source of the nutrient for people who are unable to get enough from sun exposure and diet.
Vitamin D deficiency is real, but there’s no epidemic
Some people who promote vitamin D supplements claim that vitamin D deficiency is an epidemic causing widespread health issues. There is little evidence to support this claim. A 2022 analysis of 2001-2018 data found that 2.6 percent of people in the U.S. had severe vitamin D deficiency.
Severe vitamin D deficiency can cause serious health issues, such as muscle weakness, bone loss in adults, and rickets (weak bones) in children. Some people are at higher risk for the deficiency, including individuals with certain disorders that prevent the body from absorbing or processing vitamin D or those with a family history of vitamin D deficiency.
Black Americans have the highest rates of severe vitamin D deficiency at nearly 12 percent. Severe vitamin D deficiency is also slightly higher in the U.S. during the winter when people get less sun exposure. Rates of moderate vitamin D deficiency are higher at 22 percent overall and are highest among Black Americans (49 percent) and Mexican Americans (35 percent).
Although severe vitamin D deficiency exists in the U.S., it is far from common. Most tellingly, conditions that are directly linked to vitamin D deficiency are not widespread. There is no epidemic of rickets, for example, or bone loss in adults.
There’s little evidence that vitamin D supplements improve overall health
Vitamin D supplements have clear, proven positive effects for people with vitamin D deficiency. Other health benefits of vitamin D supplements are less certain.
There is some evidence that the supplement may reduce the risk of fracture in adults with osteoporosis, a condition that causes weak, fragile bones. However, the benefit appears to be limited to people who have low vitamin D levels. In adults with normal vitamin D levels, supplements have no effect on fracture risk.
The largest randomized controlled trial of vitamin D, called VITAL, investigated the effects of vitamin D supplementation in people without an existing deficiency. The study found that vitamin D supplements had no effects on the risk of cancer, diabetes, or cardiovascular disease, including heart attack and stroke. The study concluded that more research is necessary to determine who may benefit from vitamin D supplements.
Independent analyses found that vitamin D supplementation may be associated with a long-term decrease in cancer mortality, but results are mixed and also require more investigation.
A 2021 analysis of past vitamin D trials found no overall health benefits from vitamin D supplements in people with normal vitamin D levels. Most large-scale studies have found no link between vitamin D supplements and lower all-cause mortality (deaths from any cause), except in older adults and those with vitamin D deficiency.
Vitamin D provides modest protection against respiratory infections
Vitamin D is important for immune function, but this is often misconstrued as vitamin D “boosting” the immune system.
Some people falsely believe that taking vitamin D supplements will keep them healthy and prevent infections like the flu or COVID-19. In reality, clinical trials and large-scale studies of vitamin D have found only minimal protective effects against respiratory infections.
A 2021 analysis of 46 trials found that 61.3 percent of participants who took daily vitamin D supplements got respiratory infections during the study periods—compared to 62.3 percent of people who did not take the supplements. A 2024 meta-analysis of 43 trials found no overall protective effect against respiratory infections, but it detected a slight decrease in risk among people who took specific doses daily.
In young children, there is some evidence that vitamin D supplementation may reduce the length of respiratory infections. However, it does not affect the number or severity of infections that children have.
Despite claims that taking vitamin D can protect against COVID-19, two clinical trials found that taking daily vitamin D supplements did not reduce the risk or severity of COVID-19 infections, even at high doses.
Context is key when considering vitamin D’s benefits
None of these studies contradict the well-established evidence that people with vitamin D deficiency benefit from vitamin D supplements. But it’s important to remember that many of the most popular health claims about vitamin D’s benefits are based on research in people with vitamin D deficiency.
Research in vitamin D-deficient populations is important, but it tells us little about how vitamin D will affect people with normal or close to normal vitamin D levels. A closer look at vitamin D research in people without low levels reveals little evidence to support the idea that the general population benefits from taking vitamin D supplements.
For more information, or to learn about your vitamin D levels, talk to your health care provider.
This article first appeared on Public Good News and is republished here under a Creative Commons license.
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Peach vs Papaya – Which is Healthier?
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Our Verdict
When comparing peach to papaya, we picked the peach.
Why?
It was close!
In terms of macros, there’s not much between them; they are close to identical on protein, carbs, and fiber. Technically peach has slightly more protein (+0.4g/100g) and papaya has slightly more carbs and fiber (+1.28g/100g carbs, +0.2g/100g fiber), but since the differences are so tiny, we’re calling this section a tie—bearing in mind, these numbers are based on averages, which means that when they’re very close, they’re meaningless—one could easily, for example, pick up a peach that has more fiber than a papaya, because that 0.2g/100g is well within the margin of variation. So, as we say: a tie.
When it comes to vitamins, things are also close; peaches have more of vitamins B1, B2, B3, and E, while papaya has more of vitamins A, B6, B9, and C. This is a 4:4 tie, but since the most notable margin of difference is vitamin C (of which papayas have 9x more) while the others are much closer, we’ll call this a tie-breaker win for papaya.
The category of minerals sets things apart more: peaches have more copper, iron, manganese, phosphorus, potassium, and zinc, while papaya has more calcium, magnesium, and selenium. That’s already a 6:3 win for peaches, before we take into account that the numbers for papaya’s calcium and selenium are tiny, so adding this to the already 6:3 win for peaches makes for a clear and easy win for peaches in this category.
Adding up the sections is 1W/1D/1L for both fruits, but looking at the win/loss for each, it’s clear which won/lost on a tiebreaker, and which won/lost by a large margin, so peaches get the victory here.
Of course, enjoy either or both, though! And see below for a bonus feature of peaches:
Want to learn more?
You might like to read:
Top 8 Fruits That Prevent & Kill Cancer ← peaches are high on this list! They kill cancer cells while sparing healthy ones 🙂
Take care!
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Lies I Taught in Medical School – by Dr. Robert Lufkin
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There seems to be a pattern of doctors who practice medicine one way, get a serious disease personally, and then completely change their practice of medicine afterwards. This is one of those cases.
Dr. Lufkin here presents, on a chapter-by-chapter basis, the titularly promised “lies” or, in more legally compliant speak (as he acknowledges in his preface), flawed hypotheses that are generally taught as truths. In many cases, the “lie” is some manner of “xyz is normal and nothing to worry about”, and/or “there is nothing to be done about xyz; suck it up”.
The end result of the information is not complicated—enjoy a plants-forward whole foods low-carb diet to avoid metabolic diseases and all the other things to branch off from same (Dr. Lufkin makes a fair case for metabolic disease leading to a lot of secondary diseases that aren’t considered metabolic diseases per se). But, the journey there is actually important, as it answers a lot of questions that are much less commonly understood, and often not even especially talked-about, despite their great import and how they may affect health decisions beyond the dietary. Things like understanding the downsides of statins, or the statistical models that can be used to skew studies, per relative risk reduction and so forth.
Bottom line: this book gives the ins and outs of what can go right or wrong with metabolic health and why, and how to make sure you don’t sabotage your health through missing information.
Click here to check out Lies I Taught In Medical School, and arm yourself with knowledge!
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Teriyaki Chickpea Burgers
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Burgers are often not considered the healthiest food, but they can be! Ok, so the teriyaki sauce component itself isn’t the healthiest, but the rest of this recipe is, and with all the fiber this contains, it’s a net positive healthwise, even before considering the protein, vitamins, minerals, and assorted phytonutrients.
You will need
- 2 cans chickpeas, drained and rinsed (or 2 cups of chickpeas, cooked drained and rinsed)
- ¼ cup chickpea flour (also called gram flour or garbanzo bean flour)
- ¼ cup teriyaki sauce
- 2 tbsp almond butter (if allergic, substitute with a seed butter if available, or else just omit; do not substitute with actual butter—it will not work)
- ½ bulb garlic, minced
- 1 large chili, minced (your choice what kind, color, or even whether or multiply it)
- 1 large shallot, minced
- 1″ piece of ginger, grated
- 2 tsp teriyaki sauce (we’re listing this separately from the ¼ cup above as that’ll be used differently)
- 1 tsp yeast extract (even if you don’t like it; trust us, it’ll work—this writer doesn’t like it either but uses it regularly in recipes like these)
- 1 tbsp black pepper
- 1 tsp fennel powder
- ½ tsp sweet cinnamon
- ½ tsp MSG or 1 tsp low-sodium salt
- Extra virgin olive oil for frying
For serving:
- Burger buns (you can use our Delicious Quinoa Avocado Bread recipe)
- Whatever else you want in there; we recommend mung bean sprouts, red onion, and a nice coleslaw
Method
(we suggest you read everything at least once before doing anything)
1) Preheat the oven to 400℉ / 200℃.
2) Roast the chickpeas spaced out on a baking tray (lined with baking paper) for about 15 minutes. Leave the oven on afterwards; we still need it.
3) While that’s happening, heat a little oil in a skillet to a medium heat and fry the shallot, chili, garlic, and ginger, for about 2–3 minutes. You want to release the flavors, but not destroy them.
4) Let them cool, and when the chickpeas are done, let them cool for a few minutes too, before putting them all into a food processor along with the rest of the ingredients from the main section, except the oil and the ¼ cup teriyaki sauce. Process them into a dough.
5) Form the dough into patties; you should have enough dough for 4–6 patties depending on how big you want them.
6) Brush them with the teriyaki sauce; turn them onto a baking tray (lined with baking paper) and brush the other side too. Be generous.
7) Bake them for about 15 minutes, turn them (taking the opportunity to add more teriyaki sauce if it seems to merit it) and bake for another 5–10 minutes.
8) Assemble; we recommend the order: bun, a little coleslaw, burger, red onion, more coleslaw, mung bean sprouts, bun, but follow your heart!
Enjoy!
Want to learn more?
For those interested in some of the science of what we have going on today:
- Three Daily Servings of Beans/Legumes?
- Hoisin Sauce vs Teriyaki Sauce – Which is Healthier?
- Sprout Your Seeds, Grains, Beans, Etc
- Our Top 5 Spices: How Much Is Enough For Benefits? ← we scored 4/5 today!
- Monosodium Glutamate: Sinless Flavor-Enhancer Or Terrible Health Risk?
Take care!
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Our blood-brain barrier stops bugs and toxins getting to our brain. Here’s how it works
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Our brain is an extremely complex and delicate organ. Our body fiercely protects it by holding onto things that help it and keeping harmful things out, such as bugs that can cause infection and toxins.
It does that though a protective layer called the blood-brain barrier. Here’s how it works, and what it means for drug design.
The Conversation, Rattiya Thongdumhyu/Shutterstock, Petr Ganaj/Pexels First, let’s look at the circulatory system
Adults have roughly 30 trillion cells in their body. Every cell needs a variety of nutrients and oxygen, and they produce waste, which needs to be taken away.
Our circulatory system provides this service, delivering nutrients and removing waste.
Fenestrated capillaries let nutrients and waste pass through. Vectormine/Shutterstock Where the circulatory system meets your cells, it branches down to tiny tubes called capillaries. These tiny tubes, about one-tenth the width of a human hair, are also made of cells.
But in most capillaries, there are some special features (known as fenestrations) that allow relatively free exchange of nutrients and waste between the blood and the cells of your tissues.
It’s kind of like pizza delivery
One way to think about the way the circulation works is like a pizza delivery person in a big city. On the really big roads (vessels) there are walls and you can’t walk up to the door of the house and pass someone the pizza.
But once you get down to the little suburban streets (capillaries), the design of the streets means you can stop, get off your scooter and walk up to the door to deliver the pizza (nutrients).
We often think of the brain as a spongy mass without much blood in it. In reality, the average brain has about 600 kilometres of blood vessels.
The difference between the capillaries in most of the brain and those elsewhere is that these capillaries are made of specialised cells that are very tightly joined together and limit the free exchange of anything dissolved in your blood. These are sometimes called continuous capillaries.
Continuous capillaries limit the free exchange of anything dissolved in your blood. Vectormine/Shutterstock This is the blood brain barrier. It’s not so much a bag around your brain stopping things from getting in and out but more like walls on all the streets, even the very small ones.
The only way pizza can get in is through special slots and these are just the right shape for the pizza box.
The blood brain barrier is set up so there are specialised transporters (like pizza box slots) for all the required nutrients. So mostly, the only things that can get in are things that there are transporters for or things that look very similar (on a molecular scale).
The analogy does fall down a little bit because the pizza box slot applies to nutrients that dissolve in water. Things that are highly soluble in fat can often bypass the slots in the wall.
Why do we have a blood-brain barrier?
The blood brain barrier is thought to exist for a few reasons.
First, it protects the brain from toxins you might eat (think chemicals that plants make) and viruses that often can infect the rest of your body but usually don’t make it to your brain.
It also provides protection by tightly regulating the movement of nutrients and waste in and out, providing a more stable environment than in the rest of the body.
Lastly, it serves to regulate passage of immune cells, preventing unnecessary inflammation which could damage cells in the brain.
What it means for medicines
One consequence of this tight regulation across the blood brain barrier is that if you want a medicine that gets to the brain, you need to consider how it will get in.
There are a few approaches. Highly fat-soluble molecules can often pass into the brain, so you might design your drug so it is a bit greasy.
The blood-brain barrier stops many medicines getting into the brain. Ron Lach/Pexels Another option is to link your medicine to another molecule that is normally taken up into the brain so it can hitch a ride, or a “pro-drug”, which looks like a molecule that is normally transported.
Using it to our advantage
You can also take advantage of the blood brain barrier.
Opioids used for pain relief often cause constipation. They do this because their target (opioid receptors) are also present in the nervous system of the intestines, where they act to slow movement of the intestinal contents.
Imodium (Loperamide), which is used to treat diarrhoea, is actually an opioid, but it has been specifically designed so it can’t cross the blood brain barrier.
This design means it can act on opioid receptors in the gastrointestinal tract, slowing down the movement of contents, but does not act on brain opioid receptors.
In contrast to Imodium, Ozempic and Victoza (originally designed for type 2 diabetes, but now popular for weight-loss) both have a long fat attached, to improve the length of time they stay in the body.
A consequence of having this long fat attached is that they can cross the blood-brain barrier, where they act to suppress appetite. This is part of the reason they are so effective as weight-loss drugs.
So while the blood brain barrier is important for protecting the brain it presents both a challenge and an opportunity for development of new medicines.
Sebastian Furness, ARC Future Fellow, School of Biomedical Sciences, The University of Queensland
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Antihistamines for Runny Nose?
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It’s Q&A Day at 10almonds!
Have a question or a request? We love to hear from you!
In cases where we’ve already covered something, we might link to what we wrote before, but will always be happy to revisit any of our topics again in the future too—there’s always more to say!
As ever: if the question/request can be answered briefly, we’ll do it here in our Q&A Thursday edition. If not, we’ll make a main feature of it shortly afterwards!
So, no question/request too big or small 😎
❝Do you have any articles about using Anti-Histamines? My nose seems to be running a lot. I don’t have a cold or any allergies that I know of. I tried a Nasal spray Astepro, but it doesn’t do much.?❞
Just for you, we wrote such an article yesterday in response to this question!
The Astepro that you tried, by the way, is a brand name of the azelastine we mentioned near the end, before we got to talking about systemic corticosteroids such as beclometasone dipropionate—this latter might help you if antihistamines haven’t, and if your doctor advises there’s no contraindication (for most people it is safe for there are exceptions, such as if you are immunocompromised and/or currently fighting some infection).
You can find more details on all this in yesterday’s article, which in case you missed it, can be found at:
Antihistamines’ Generation Gap: Are You Ready For Allergy Season?
Enjoy!
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Why Some People Get Sick More (And How To Not Be One Of Them)
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Some people have never yet had COVID (so far so good, this writer included); others are on their third bout already; others have not been so lucky and are no longer with us to share their stories.
Obviously, even the healthiest and/or most careful person can get sick, and it would be folly to be complacent and think “I’m not a person who gets sick; that happens to other people”.
Nor is COVID the only thing out there to worry about; there’s always the latest outbreak-du-jour of something, and there are always the perennials such as cold and flu—which are also not to be underestimated, because both weaken us to other things, and flu has killed very many, from the 50,000,000+ in the 1918 pandemic, to the 700,000ish that it kills each year nowadays.
And then there are the combination viruses:
Move over, COVID and Flu! We Have “Hybrid Viruses” To Contend With Now
So, why are some people more susceptible?
Firstly, some people are simply immunocompromised. This means for example that:
- perhaps they have an inflammatory/autoimmune disease of some kind (e.g. lupus, rheumatoid arthritis, type 1 diabetes), or…
- perhaps they are taking immunosuppressants for some reason (e.g. because they had an organ transplant), or…
- perhaps they have a primary infection that leaves them vulnerable to secondary infections. Most infections will do this to some degree or another, but some are worse for it than others; untreated HIV is a clear example. The HIV itself may not kill people, but (if untreated) the resultant AIDS will leave a person open to being killed by almost any passing opportunistic pathogen. Pneumonia of various kinds being high on the list, but it could even be something as simple as the common cold, without a working immune system to fight it.
See also: How To Prevent (Or Reduce) Inflammation
And for that matter, since pneumonia is a very common last-nail-in-the-coffin secondary infection (especially: older people going into hospital with one thing, getting a secondary infection and ultimately dying as a result), it’s particularly important to avoid that, so…
See also: Pneumonia: What We Can & Can’t Do About It
Secondly, some people are not immunocompromised per the usual definition of the word, but their immune system is, arguably, compromised.
Cortisol, the stress hormone, is an immunosuppressant. We need cortisol to live, but we only need it in small bursts here and there (such as when we are waking up the morning). When high cortisol levels become chronic, so too does cortisol’s immunosuppressant effect.
Top things that cause elevated cortisol levels include:
- Stress
- Alcohol
- Smoking
Thus, the keys here are to 1) not smoke 2) not drink, ideally, or at least keep consumption low, but honestly even one drink will elevate cortisol levels, so it’s better not to, and 3) manage stress.
See also: Lower Your Cortisol! (Here’s Why & How)
Other modifiable factors
Being aware of infection risk and taking steps to reduce it (e.g. avoiding being with many people in confined indoor places, masking as appropriate, handwashing frequently) is a good preventative strategy, along with of course getting any recommended vaccines as they come available.
What if they fail? How can we boost the immune system?
We talked about not sabotaging the immune system, but what about actively boosting it? The answer is yes, we certainly can (barring serious medical reasons why not), as there are some very important lifestyle factors too:
Beyond Supplements: The Real Immune-Boosters!
One final last-line thing…
Since if we do get an infection, it’s better to know sooner rather than later… A recent study shows that wearable activity trackers can (if we pay attention to the right things) help predict disease, including highlighting COVID status (positive or negative) about as accurately (88% accuracy) as rapid screening tests. Here’s a pop-science article about it:
Wearable activity trackers show promise in detecting early signals of disease
Take care!
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