Megadosing Vitamin D: 

don’t try this at home 

So, I recently discovered that my vitamin D levels are at 15.7 ng/mL. Not ideal 

According to the Institute of Medicine (IOM), anything below 20 ng/mL (50 nmol/L) is considered deficient (IOM, 2011), which means I’m officially in the “severely deficient” category. Yay, me. 

Now, you might think, but Karan, you’re a doctor, how did this happen?! 

Well, it turns out that living in the UK (where sunlight is more of a rumor than a reality) and having darker skin (which naturally produces less vitamin D from sunlight) is the perfect recipe for becoming a human version of a solar-powered device stuck in a basement. 

My experimental regimen (rot medical advice): 

• 17,000 IU of Vitamin D3 (with K2) daily for 12 days 

• Then dropping to a maintenance dose of 6,000 IU daily 

• Regular monitoring: I’ll recheck my blood levels a month after starting to see if my bones are happy or plotting a rebellion 

• Hypercalcemia watch: I’ll be on the lookout for symptoms like “stones, bones, groans, and psychiatric overtones”—aka kidney stones, bone pain, abdominal discomfort, and mood changes 

Disclaimer: This is not medical advice. This is me, conducting a personal experiment, under supervision, after discussing with experts. Do not copy me and always ensure you’ve consulted your own doctor, ideally one who doesn’t roll their eyes. 

Why Am I Doing This? 

Because I’m curious. I don’t feel any obvious symptoms of deficiency—no bone pain, no muscle weakness—but I’m wondering if bringing my levels back to normal will improve things like: 

• Mood: Is my existential dread because of vitamin D deficiency, or is it just… living in the UK? 

• Energy levels: Will I finally have the motivation to fold laundry instead of staring at it for days? 

• General well-being: Will sunlight stop feeling like an exotic luxury? 

The science of vitamin D: not just the “sunshine vitamin” 

Vitamin D is technically a hormone, not just a vitamin. It’s synthesized when your skin is exposed to UVB radiation from the sun. But here’s the thing—you don’t need to sunbathe like a lizard for hours. Just a few minutes of sun exposure (arms, face, legs) can produce enough vitamin D for most people. 

And if you don’t get enough sun? Your body’s got backup plans: 

1. Stored reserves: Vitamin D is stored in your liver and fat cells for rainy days (or, you know, entire British winters). 

2. Dietary sources: Fatty fish (salmon, mackerel, sardines), egg yolks, liver, red meat, and fortified foods like dairy and cereals. 

But here’s where it gets tricky: 

• Darker skin = more melanin = natural sunblock = less vitamin D synthesis 

• Living far from the equator = less UVB exposure 

So, yeah, if you’re like me—dark-skinned, living in the UK, and occasionally mistaking a desk lamp for the sun—you’re at risk. 

What do the guidelines say? 

• IOM (2011): Deficiency <20 ng/mL; insufficiency 20–30 ng/mL 

• Endocrine Society (2011): For severe deficiency, recommend 50,000 IU/week or 6,000 IU/day for 8 weeks, then maintenance of 1,500–2,000 IU/day (Holick et al., 2011) 

• My plan? Slightly more aggressive. 17,000 IU daily for 12 days is roughly equivalent to the weekly 50,000 IU dose but spread out. Then I’ll drop to 6,000 IU for maintenance and adjust based on follow-up blood tests. 

Why add vitamin K2 and magnesium? 

• Vitamin K2: Think of vitamin D as the delivery truck for calcium, and K2 as the GPS that ensures the calcium goes to your bones, not your arteries. Without K2, there’s a theoretical risk of vascular calcification. 

• Magnesium: It’s a cofactor required for vitamin D metabolism. Low magnesium can make vitamin D less effective and might even cause symptoms like cramps and fatigue. 

Best practices for taking Vitamin D: 

1. Take with food (preferably fatty): Vitamin D is fat-soluble, so it absorbs better with a meal. 

2. Consistency is key: Don’t treat supplements like your gym membership—neglected after the first week. 

3. Monitor for signs of toxicity: 

• "Stones" = kidney stones 

• "Bones" = bone pain 

• "Groans" = abdominal pain, nausea 

• "Psychiatric overtones" = confusion, mood changes 

4. Recheck blood levels after 4–8 weeks: Adjust dose based on the results. 

The bottom line: 

• Excess vitamin D won’t make you superhuman, but correcting a deficiency can improve bone health, immune function, and possibly mood and energy. 

• Megadosing isn’t necessary for everyone. In fact, it can be dangerous if done recklessly. Talk to your doctor before starting high doses. This isn’t Hogwarts. 

• Get your vitamin D levels checked—don’t just guess. 

• If deficient, follow evidence-based guidelines for replacement. 

• Add K2 and magnesium to support vitamin D metabolism. 

• Sunlight is free (when available)—use it wisely. 

For me, this is an experiment to see how my body responds. Maybe I’ll feel more energized. Maybe I’ll just be slightly less grumpy. Or maybe I’ll realize that no amount of vitamin D can fix the fact that I live in the UK. 

“Natural Ozempic” is not a thing... 

Welcome to the latest episode of “society’s obsession with quick fixes” where we desperately try to turn kale, chia seeds, and probably moon dust into pharmaceutical-grade miracle drugs. Today’s contestant? Natural Ozempic 

If you’ve been doom-scrolling through social media, you’ve probably seen the claims: 

"This magical tea mimics Ozempic!" 

"Eat this ancient grain and watch the pounds melt away—just like a GLP-1 receptor agonist would!" 

Let me stop you right there. No. No, it doesn’t. 

What is ozempic, and why are people obsessed? 

For those who’ve blissfully avoided TikTok health gurus: 

Ozempic (semaglutide) is a GLP-1 receptor agonist, originally designed to manage type 2 diabetes but now famous for its impressive weight loss effects. It works by: 

• Mimicking GLP-1 (Glucagon-like Peptide-1): A hormone that increases insulin secretion, slows gastric emptying, and reduces appetite. 

• Powerfully suppressing hunger: Think of it as the appetite’s off-switch—except it’s not just flipping a switch; it’s rewiring the entire circuit board. 

Now, let’s talk about why a chia seed smoothie isn’t going to do the same thing. 

Why natural Ozempic is overhyped and inaccurate 

• Ozempic is a pharmaceutical-grade, lab-engineered molecule that binds to GLP-1 receptors with laser-like precision, designed to stay active in your system for up to a week. 

• No food, no herb, no ancient root dug from the sacred soils of Instagram wellness pages can replicate this. 

Sure, certain foods can stimulate your body’s natural GLP-1 production—but the effect is like comparing a sparkler to a firework finale. 

• Foods = quick flicker of GLP-1, lasting minutes to a few hours. 

• Ozempic = sustained hormonal symphony, playing non-stop in the background. 

The science: how foods can boost satiety (but not like Ozempic) 

While there’s no “natural Ozempic,” you can hack your satiety signals with certain foods. Here’s how: 

1. Fiber: the gut’s unsung hero 

• How it works: Fiber, especially soluble fiber, gets fermented by your gut bacteria into short-chain fatty acids (SCFAs) like butyrate. 

• SCFAs stimulate L-cells in your intestines to release satiety hormones like GLP-1, PYY (Peptide YY), and CCK (Cholecystokinin) (Chambers et al., Gut, 2015). 

• Effect: A modest, temporary appetite reduction—not the long-lasting suppression seen with drugs like Ozempic. 

Foods to focus on: 

• E.g Oats, lentils, chia seeds, flaxseeds, apples etc 

2. Protein: the satiety superstar 

• How it works: Protein triggers the release of PYY and GLP-1, and also reduces the hunger hormone ghrelin (Leidy et al., American Journal of Clinical Nutrition, 2015). 

• Effect: makes you feel fuller for longer, but again—this is a meal-to-meal effect, not a week-long appetite freeze. 

Foods to focus on: 

• Lean meats, eggs, Greek yogurt, tofu, legumes etc 

3. Fats: the slow-burn fuel 

• How it works: Dietary fats stimulate CCK release, which slows down gastric emptying, making you feel full (Little et al., Diabetes Care, 2014). 

• Effect: prolongs satiety, but don’t overdo it—calories still count. 

Foods to focus on: 

• Avocados, nuts, olive oil, fatty fish etc 

4. The “gut-brain axis” effect 

• How it works: Your gut is lined with enteroendocrine cells that communicate with your brain. Fermented foods may support healthy gut microbiota, indirectly influencing appetite regulation. 

• Effect: Possibly subtle mood and appetite shifts, but no microbial kombucha is out here mimicking Ozempic. 

Foods to focus on: 

• Kimchi, sauerkraut, kefir, yogurt etc 

The psychology: why we crave quick fixes 

The “natural Ozempic” trend isn’t just about weight loss. It’s a symptom of a society obsessed with immediate gratification, shortcut culture and a deep mistrust of anything synthetic, even when it’s evidence-based 

We love the illusion of control—the belief that the right smoothie recipe will unlock metabolic nirvana. But biology doesn’t work like that. You can’t out-fiber a GLP-1 receptor agonist. 

Evidence-based actionables (without the hype): 

1. Eat more soluble Fiber: Aim for 25–30g/day (Chambers et al., 2015). 

2. Prioritize protein: 20–30g per meal to optimize satiety signals (Leidy et al., 2015). 

3. Healthy fats for the win: Add moderate amounts to slow digestion and support hormone release. 

4. Meal timing matters: Regular meals help regulate satiety hormones effectively. 

5. Sleep and stress: Poor sleep and chronic stress mess with hunger hormones like ghrelin and cortisol. 

If someone’s trying to sell you “natural Ozempic” in a bottle, bar, or berry, just know you’re buying into a fantasy. 

• Ozempic is a drug. 

• Broccoli is broccoli. 

• No amount of chia seeds will replace pharmacology. 

Unless you can convince your pancreas to start moonlighting as a pharmaceutical factory. In which case—call me. We’ll patent it.  

P.S to learn more about health & science in easy to digest ways check out my book:

Something I Wish I Knew Before I Was In My 30s... 

You’ll suck at first...and that’s the point. 

Here’s an inconvenient truth that would’ve saved me years of existential spiraling: you’re going to be terrible at pretty much everything the first time you try it. I don’t care if it’s starting a business, learning an instrument, baking sourdough, or attempting to parallel park without causing an emotional crisis—you’ll suck. Badly. 

Take me, for example. 

In my early days of social media, I was the human equivalent of a Wi-Fi signal in a basement. Disorganized. Cringeworthy. About as coherent as a toddler explaining quantum physics. I’d post content with all the finesse of someone who thinks hashtags are a personality trait. 

But that’s how it’s supposed to be. 

The myth of “natural talent”  

We love the idea of natural-born geniuses. It’s comforting to think that Olympic athletes were born doing backflips, or that Mozart popped out of the womb composing symphonies. But even the greats were garbage at first. 

• Michael Phelps? Once a gangly kid flailing in a pool. 

• Serena Williams? Missed more shots than she landed when she started. 

• Me? Thought “engagement” was something that happened when people got married, not a metric. 

Sure, there’s some genetic variance in IQ, coordination, or whatever. But talent is mostly a myth we tell ourselves to avoid the painful truth: skills are built, not born. 

The science of sucking (and eventually getting better) 

Let’s touch on the neuroscience of going from trash to treasure... 

• Your brain is basically a lump of squishy Play-Doh with electricity running through it. 

• Every time you try something new, your neurons fire off like confused toddlers with glow sticks. 

• This chaos is called “neuroplasticity.” It’s your brain’s ability to rewire itself. At first, the connections are weak—like a dodgy bluetooth connection. But the more you repeat a task, the stronger those connections get, until eventually, you don’t even have to think about it. 

The secret? It’s all about reps, not genius. Mastery isn’t just inspiration, it’s boring repetition. 

This process is why: 

• Babies can’t walk straight out of the womb. 

• You can’t play the guitar perfectly after watching one YouTube tutorial. 

• My first TikTok videos looked like they were made during an earthquake. 

How to suck less over time: 

1. Start ugly: 

Stop waiting to be “ready.” You won’t be. Launch the blog. Record the podcast. Write the bad first draft. 

2. Track progress, not perfection: 

Instead of focusing on being “good,” focus on getting 1% better every day..or 0.1% 

3. Seek failure on purpose: 

If you’re not failing, you’re not trying hard enough. Failure isn’t a bug; it’s the feature. 

4. Reframe the narrative: 

Don’t think, “I’m bad at this.” Think, “I’m pre-successful.” 

5. Embrace the plateau: 

Progress isn’t linear. There will be days where you feel stuck. That’s your brain consolidating skills. Keep going. 

If you’re avoiding something because you’re scared of being bad at it, congratulations—you’ve found exactly what you should be doing. Growth isn’t comfortable. It’s awkward, messy, and full of mistakes. 

Every expert or peak performer once had no idea what they were doing in the thing they were doing.  

And me? I was once terrible at social media. Now I’m just… slightly less terrible. 

And that’s progress. 

Everything You’re Getting Wrong About Sleep... 

For something we spend a third of our lives doing, we understand sleep about as well as we understand black holes—which is to say, badly. 

But there are a few myths about sleep which permeate like a bad smell in a flight... 

1. You can train your body to need less sleep—No, you can’t. Stop It. 

Somewhere along the way, we romanticized sleep deprivation. CEOs brag about surviving on four hours of sleep, college students treat all-nighters like Olympic events, and there’s always that one person who claims, “I function perfectly fine on five hours.” 

No, they’re not fine. 

They’ve just forgotten what “fine” feels like because their brain has been operating in “potato mode” for so long. 

Sure, you can cope with less sleep. You can drown yourself in caffeine, adopt an emotional support energy drink, or convince yourself that skipping sleep is “grindset” behavior. But you’re not sidestepping the damage. You’re just numbing the symptoms. 

What actually happens when you’re sleep-deprived: 

• Memory turns to mush: Your hippocampus is basically trying to file paperwork while drunk. 

• Mood swings: You’re one skipped nap away from an emotional meltdown because your prefrontal cortex has clocked out. 

• Creativity nosedives: Good luck having groundbreaking ideas when your brain feels like it’s buffering. 

So no, you can’t “train” your body to need less sleep. You can only train yourself to function like a poorly coded app—technically operational, but prone to crashes. 

2. Waking up at 3 AM doesn’t mean you’re broken 

You jolt awake at 3 AM. You check the time, sigh dramatically, and wonder if your circadian rhythm is in a toxic relationship with you. But... 

Waking up during the night is NORMAL. 

Your sleep isn’t a continuous Netflix binge. It’s more like a series of episodes with occasional commercial breaks. Sleep cycles (light sleep, deep sleep, REM) naturally cause brief awakenings. It’s biology’s way of making sure you’re not dead, because, you know—evolution. 

Common reasons you wake up: 

• Bathroom breaks: congratulations, your bladder works. 

• Temperature changes: Too hot? Too cold? Welcome to being human. 

• Random nihilistic dread: A fan favorite. 

What should you do? 

• If you’re awake for more than 15–20 minutes, get out of bed. 

• Read a book (preferably something boring—don’t start a thriller unless you want to be awake till dawn). 

• Resist the urge to doom-scroll on your phone because blue light turns your melatonin into a sleep-deprived gremlin. 

3. More sleep isn’t always better  

If you think sleeping 12 hours on weekends is the pinnacle of health, think again. 

Oversleeping can be just as problematic as not sleeping enough. 

Consistently needing excessive sleep might be a sign that your sleep quality is garbage. It’s like eating an entire cake because you’re still hungry—it’s not about the quantity; it’s about the quality. 

Possible culprits: 

• Sleep Apnea: Your airway collapses during sleep, causing micro-awakenings that ruin deep rest. 

• Depression: Oversleeping is often a coping mechanism for mental health struggles. 

• Fragmented Sleep: You might be technically “asleep” but not reaching restorative stages. 

Pro Tip: 

If you regularly need more than 9–10 hours of sleep to feel human, it’s worth talking to a sleep specialist. You might have a sleep disorder—not just an impressive napping skill. 

We treat sleep like it’s a luxury spa treatment when it’s actually more like basic brain maintenance. 

So, go to bed. 

Not because it’s trendy. 

Not because your smartwatch told you to. 

But because your brain deserves better than being treated like a malfunctioning hoover. 

Sweet dreams—or, at the very least, functional ones. 

P.S check out the most recent podcast episode all about sleep:

Which Diet Gives You The Best Gut Health? 

... Your gut doesn’t care about your dietary labels 

It turns out that your gut microbiome—yes, that teeming metropolis of trillions of bacteria squatting rent-free in your intestines—doesn’t give a fermented fig whether you’re vegan, vegetarian, or an omnivore. What it really cares about is simple: the quality and diversity of the food you shovel into your mouth. 

A new study, featuring an impressive 21,561 people from the USA, UK, and Italy (aka the Holy Trinity of pizza, processed snacks, and passive-aggressive tea culture), has revealed that it’s not your dietary identity that matters—it’s how many actual plants you’re eating.  

Sorry but just calling yourself vegan doesn’t earn you automatic gut health points if your diet consists solely of fries and oat milk lattes. 

The study: poop, plants, and machine learning 

Researchers bravely dived into the world of stool samples—because apparently, the path to scientific enlightenment is paved with poop. Using a method called shotgun metagenomics (which sounds like an extreme sport but is actually just advanced DNA sequencing), they analyzed microbial DNA from those 21,561 participants. Think CSI: Gut Edition. 

They paired this with self-reported dietary patterns, which means somewhere, a scientist had to seriously read, “breakfast: two Pop-Tarts” 

What did they find? (besides an uncomfortable amount of data on poop) 

1. Plant-based diversity wins: 

• It’s not whether you’re vegan, vegetarian, or omnivore. 

• It’s how many healthy, plant-based foods you cram into your face. 

• More plants = more beneficial bacteria = happier gut = less chance of dying dramatically early. 

2. Vegan guts: the gut biodome: 

• Vegans had more bacteria that produce short-chain fatty acids (SCFAs), the gut’s equivalent of magical unicorn dust that promotes heart health. 

• Their microbes are basically the overachievers of the bacterial world, hosting parties with fiber and producing anti-inflammatory compounds. 

3. Meat-lovers: the gut gladiators: 

• Red meat eaters? More bacteria specialized in digesting meat, which sounds cool until you realize some are linked to poorer health outcomes (hence why moderation is key) 

• Their gut bacteria are like that one friend who thrives on chaos—great at handling a BBQ, not so great at long-term health. 

4. Vegetarians: the middle child of microbiomes: 

• Their gut signature sat neatly between vegans and omnivores—kind of like being the diplomatic middle child in a family feud over who’s healthier. 

But wait, there’s more... 

Here’s the wild part: Your food doesn’t just feed your gut bacteria. It brings its own bacteria to the party. 

• Dairy products? Loaded with bacteria like Streptococcus thermophilus (fancy yogurt germs). 

• Fruits and vegetables? Tiny microbial hitchhikers from soil and plant surfaces sneak into your gut. 

• Omnivores and vegetarians who consume dairy, fruits, and veggies had more food-associated microbes than vegans—who apparently have the most “clean” microbiomes because their food is less likely to come with a microbial plus-one. 

So next time someone brags about their “clean eating,” just remember: 

The dirtier your vegetables, the more diverse your gut. (Don’t actually eat dirt though, unless you’re into that sort of thing.) 

The big takeaway 

Your gut doesn’t care about your moral high ground, your Instagram aesthetic, or the fact that you only eat “artisanal gluten-free air.” 

What your gut cares about is: 

• Diversity: Eat like you’re trying to impress a picky, microscopic audience. 

• Fiber: Because your bacteria are basically fiber-fueled factories. 

• Less processed garbage: Your gut bacteria aren’t into ultra processed snacks, even if you are. 

In the end, whether you’re a kale-worshipping vegan, a quinoa-munching vegetarian, or an omnivore who thinks ketchup counts as a vegetable—it’s the plants that matter. 

So go forth, eat the rainbow (of actual plants, not just Skittles), and remember: your gut is watching. 

Dr. Karan 2.0: the self-improvement experiment nobody asked for  

You can poke a mouse with all manner of exotic anti-ageing therapies and along the way you might stumble upon some cool longevity science! But poke a man with the same anti-ageing stick?… well, you get a man googling “why do I feel like a sack of expired yogurt” at 3 AM. 

Man isn’t mouse. 

So here we are: Dr. Karan 2.0—my personal experiment in becoming a healthier, optimized version of myself. Not to transcend humanity, mind you, just to make sure as I age... my knees don’t audibly scream every time I stand up. 

Coincidentally, just before I decided to launch project, someone asked me if I’d consider dabbling with some of the medicines Bryan Johnson takes... 

My answer was simple then, and it remains simple now: 

1. Know the evidence.  

Before trying anything, ask: 

• What’s the evidence? 

• Does this make sense beyond a podcast clip? 

• Am I genuinely optimizing my health, or am I just trying to feel something because capitalism has numbed my soul? 

2. Internal before external 

No pill, potion, injection, or supplement will beat: 

• A solid cardio-respiratory function 

• Good quality sleep 

• Real food that didn’t come in a neon package 

• The revolutionary act of drinking enough water like an adult 

You can’t out-supplement a sedentary lifestyle and chronic stress. Fix your internal Wi-Fi before blaming the router. 

3. Biohacking isn’t a guaranteed path to immortality. It’s just fancy self-experimentation with better branding. 

If you’re experimenting on yourself, treat it as such: 

• Document your results. 

• Be honest about failures. 

• Know when to quit 

• Always consult experts  

Many doctors, influencers, and tech bros have been enchanted by the premature hype of longevity fads.  

Explorers sailed the seas to chase their dreams... some found new worlds; others found scurvy. 

Biohacking is the same. Some folks might discover the fountain of youth. Others will just end up peeing out expensive supplements or worse irreversibly damage their health. 

So here I am, embarking on Dr. Karan 2.0. 

No rapamycin. 

No shady peptides from underground forums. 

Just science, skepticism and learning 

Because at the end of the day, the real upgrade isn’t in the supplements. 

It’s in the questions you ask, the habits you build, and the ability to laugh at the absurdity of it all. 

You can follow along here:

P.S If you have any suggestions for things you want me to test or if you have a product you want me to give my honest opinion on, shoot me a message!

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