My Evidence-Based Supplement Stack as a Doctor: 7 Supplements That Actually Have Science Behind Them13 min read

Last month, I did something I swore I’d never do as a former internal medicine doctor—I went full supplement nerd.

Here’s the thing: throughout medical school and my time practicing internal medicine, I told patients to stick to whole foods and maybe pop some vitamin D if they lived somewhere that never saw sunlight. Supplements were the enemy. “Expensive urine,” I’d joke with colleagues. But after diving deep into recent research (and admittedly feeling burned out from my medical training), I decided to experiment on myself.

The result? I’m now taking seven supplements daily, spending about $80 per month, and honestly… I think I feel better at the gym. But here’s my reality check: this entire supplement stack probably contributes maybe 5% to my overall health and energy. The other 95% still comes from the fundamentals I’ve written about before—quality sleep, consistent exercise, good nutrition, and managing my mental health.

My morning ritual has become surprisingly simple. I start each day with two drinks that don’t taste like chalk (a victory in itself). First, I mix orange juice with vitamin C crystals, collagen, and vitamin D + K2 drops—basically a fancy adult version of orange juice. Then I chug down my second drink: 5g of creatine mixed with water and my omega-3 pill. Throughout the day, I chew 4-5 magnesium gummies like they’re Haribo bears, except these ones actually help me sleep better.

Disclaimer: None of these brands are sponsoring me, though I’ve included affiliate Amazon links throughout (meaning I earn a small percentage if you purchase through these links). This is not medical advice—I’m simply sharing my personal experiment based on my background as an internal medicine resident. Always consult your doctor before adding new supplements, and consider introducing one new supplement every two weeks.

1. The Foundation Trio: What Most Doctors Actually Recommend

Vitamin D3 + K2: The Dynamic Duo Your Bones Actually Need

What I Take: Thorne D + K2 Liquid: 2000 IU D3, 200 mcg K2

When I was practicing medicine, vitamin D was literally the only supplement I’d consistently recommend to patients. The research is overwhelming—about 42% of Americans are vitamin D deficient, with rates even higher in people with darker skin, the elderly, and those living in northern latitudes¹.

But here’s where most people (and doctors) get it wrong: taking vitamin D without K2 is like trying to build a house with only a hammer—technically possible, but you’ll probably end up with a wonky foundation. Think of it this way: vitamin D is like a very enthusiastic construction foreman that says “MORE CALCIUM! ABSORB ALL THE CALCIUM!” Meanwhile, K2 is the wise project manager who says “Great, but let’s put that calcium in your bones where it belongs, not in your arteries where it’ll cause problems.”

A 2024 clinical trial published in Circulation showed that vitamin K2 (720 μg/day) combined with D3 (25 μg/day) may help slow the progression of coronary artery calcification in high-risk patients². The K2 is crucial because research indicates that vitamin D3 supplementation without adequate K2 intake could lead to long-term health risks including arteriosclerosis and osteoporosis³.

I mix two drops into my morning orange juice, and it’s completely flavorless. My vitamin D levels went from borderline deficient (28 ng/mL) to optimal (45 ng/mL) after three months, and I genuinely feel like I get sick less often during Philadelphia winters.

Magnesium: The Mineral That Actually Lives Up to the Hype

What I Take: Trace Minerals Magnesium Gummies: 400 mg daily

Magnesium was the second supplement I’d actually prescribe to patients, usually for sleep issues or muscle cramps. A comprehensive review published in PMC found that magnesium plays important therapeutic and preventive roles in diabetes, osteoporosis, bronchial asthma, preeclampsia, migraines, sleep disorders, and cardiovascular diseases⁴.

I chew 4-5 peach-flavored gummies throughout the day (they taste dangerously good—I have to hide them from myself), and my sleep feels noticeably deeper. Here’s the simple version: magnesium is like a chill bouncer for your nervous system. When you’re stressed, your body burns through magnesium faster than I burned through my savings in medical school. Low magnesium = hyperactive nervous system = lying awake at 2 AM wondering why you said “you too” when the waiter said “enjoy your meal.”

While clinical trial evidence for magnesium’s sleep benefits is still limited, the safety profile is excellent, and the theoretical mechanisms make sense⁵. After implementing my morning routine changes and adding magnesium, I’m sleeping better than I have since medical school (which, let’s be honest, wasn’t setting a very high bar).

Creatine: The Supplement with the Strongest Evidence Base

What I Take: Naked Creatine Monohydrate: 5g daily

This one has the strongest evidence base of any supplement I take, second only to vitamin D. Think of creatine like a tiny power bank for your muscles. Your muscles use something called ATP (adenosine triphosphate) for energy—imagine ATP as the coins you need for a really expensive arcade game. Creatine helps you regenerate those “coins” faster, so you can keep playing (lifting, running, etc.) at full intensity for longer.

The International Society of Sports Nutrition’s landmark position paper found that creatine supplementation increases intramuscular creatine concentrations, which helps explain the observed improvements in high-intensity exercise performance and greater training adaptations⁶. Translation: you can do more reps, lift heavier weights, and recover faster between sets.

A major review of over 300 studies published in Molecular and Cellular Biochemistry showed that about 70% of studies report statistically significant improvements: 5-15% increases in maximal power and strength, 5-15% improvements in work performed during sets of maximal effort muscle contractions, and excellent tolerability at 3-5g daily doses⁷. Those percentages might sound small, but in the gym, that’s the difference between grinding out 8 reps versus easily hitting 10.

I mix 5g with water every morning—it’s completely flavorless and dissolves instantly. Since adding it to my routine, I’ve noticed I can push through those last few reps that used to feel impossible. Whether that’s placebo effect or real benefit, I’ll take it.

2. The Performance Enhancers: Where I Got a Bit Extra

Omega-3s: Going Vegan Because Fish Hate Me

What I Take: Nordic Naturals Algae Omega: 715mg total (EPA + DHA)

I went the vegan route with omega-3s not for ethical reasons (though props to those who do), but because I’m allergic to fish. Yes, a doctor who’s allergic to fish—it’s like being a mechanic who’s allergic to motor oil. Life has a sense of humor.

Here’s the deal with plant-based omega-3s: your body has to convert the ALA (alpha-linolenic acid) from plants into the good stuff your brain actually wants—EPA and DHA. But this conversion process is about as efficient as my attempts at cooking without setting off the smoke alarm. Research shows the conversion rate is only 5-8% for EPA and less than 0.5% for DHA⁸. So getting EPA and DHA directly from algae (which is where fish get it anyway) makes more biological sense than crossing your fingers and hoping your body converts enough flax oil.

The cardiovascular and brain health benefits of omega-3s are well-established, though you can get much of what you need from fatty fish, walnuts, and flax seeds if you’re not allergic like me⁹. I take one soft gel with breakfast, and while I can’t feel any immediate effects, I’m playing the long game for brain and heart health.

Collagen: My ACL Recovery Experiment

What I Take: Sports Research Collagen: 20g daily

I’m coming back from ACL reconstruction surgery, and while the evidence is mixed, some studies suggest collagen supplementation combined with vitamin C may support ligament healing post-surgery¹⁰. This makes intuitive sense to me—vitamin C and collagen are literally the building blocks of the quad tendon graft that became my new ACL. It’s like providing extra raw materials to a construction site where they’re rebuilding the foundation.

Think of collagen as the scaffolding that holds your body together—your skin, joints, tendons, and basically everything that keeps you from being a pile of organs on the floor. As we age, our natural collagen production slows down faster than my motivation to exercise after a long day. Research suggests supplemental collagen may improve joint pain and tendon properties, as well as support general healing throughout the body¹¹. I mix 20g into my orange juice every morning. Does it taste great? No. Am I willing to try anything that might help my knee heal better? Absolutely.

The skin benefits that people rave about? I haven’t noticed anything dramatic, but I’m more interested in getting back to running consistently than looking like I’m 22 again.

3. The “I Hate This But I Do It Anyway” Category

Protein Powder: The Necessary Evil

What I Take: Grass-Fed Whey Protein Powder: 30g per day

I genuinely despise protein shakes. They taste like someone tried to make chocolate milk but only had chalk and artificial vanilla flavoring. The texture is weird, I’d rather eat actual food 100% of the time, and every protein powder seems to promise it “tastes just like a milkshake!” (Spoiler alert: it doesn’t.)

But post-workout, when I’m exhausted, sweaty, and my brain has approximately two functioning neurons left, I choke down this grass-fed whey because it has the least “chemical laboratory” taste I’ve found. Think of protein powder as insurance for your muscles—you probably don’t need it if you’re eating enough chicken, eggs, and beans, but it’s there when life gets messy.

The protein requirements for active individuals are well-established—roughly 1.6-2.2g per kg of body weight for those doing regular resistance training¹². For context, that’s about 100-130g of protein daily for a 70kg (154lb) person who lifts regularly. I probably get enough protein from whole foods, but on heavy lifting days, this gives me peace of mind and helps me hit my macro goals without having to cook immediately after the gym.

If anyone has protein shake recipes that don’t taste like disappointment, please send them my way.

Vitamin C: The “Probably Unnecessary But Cheap” Addition

What I Take: NOW Foods Vitamin C Crystals: 1000mg

Honestly, this one’s probably as necessary as putting a screen protector on a Nokia 3310—which is to say, not at all. I eat plenty of fruits and vegetables, and most people eating a reasonably varied diet get enough vitamin C to prevent scurvy (yes, scurvy is still a thing, though thankfully rare outside of college dorm rooms during finals week).

But a 2022 meta-analysis found vitamin C supplements may reduce the duration of common cold symptoms in some populations¹³. It’s cheap as dirt, dissolves perfectly in my orange juice, and works synergistically with the collagen for potential healing benefits. I take it more out of habit than necessity at this point—it’s like wearing a belt with pants that fit perfectly. Probably unnecessary, but it gives me a tiny sense of security.

The Reality Check: What Actually Moves the Needle

Here’s what I learned after three months of this regimen: I might feel slightly more energized at the gym. I might recover a bit faster. My sleep might be deeper. But this could easily be placebo effect (which, let’s be honest, is still an effect), better stress management, or the fact that I’m finally consistent with my training again after transforming my life post-medicine.

The medical community’s stance on supplements remains unchanged and can be summarized as: “Eh, probably not necessary, but whatever makes you feel better.” Unless you have a specific deficiency or medical condition, most supplements are about as essential as having 47 different streaming services—nice to have, but not exactly life-changing. A comprehensive 2018 review emphasized that while magnesium research has focused on disease treatment, the emphasis should be on prevention through good nutrition¹⁴.

The supplement industry wants you to believe that pills can replace fundamentals. They can’t. The foundation is still quality sleep, consistent exercise, whole foods, stress management, and properly managing any health conditions you have.

Summary: The 5% Solution in a 95% World

Now, you might be wondering: “What about fiber, zinc, calcium, or iron?” I actually considered all of these, but they feel more targeted toward specific disease states or deficiencies rather than being broadly beneficial like the ones above. If you’re eating a varied diet, you’re probably getting enough. If you’re not, or if you have specific health conditions, that’s a conversation for your doctor, not your friendly neighborhood ex-doctor blogger.

I plan to continue this stack for another year to see if any long-term benefits emerge, but I’m not fooling myself—supplements are the icing, not the cake. If I had to rank the factors contributing to my health and energy:

1. Sleep quality and duration (30%) – 7-9 hours consistently
2. Regular exercise (25%) – Including both cardio and strength training
3. Nutrition from whole foods (20%) – Adequate protein, vegetables, and minimally processed foods
4. Stress management and mental health (15%) – Meditation, therapy, and boundaries
5. Supplements (5%) – This entire stack I’ve described
6. Everything else (5%) – Genetics, environment, luck

This week’s action item: Before adding any supplement, audit your basics first. Are you sleeping 7+ hours consistently? Eating enough protein and vegetables? Moving your body daily? Managing your stress? If not, save your $80/month and fix those first. As the International Society of Sports Nutrition makes clear: supplements can’t out-supplement a poor lifestyle¹⁵.

If all the fundamentals are dialed in, consider adding one supplement at a time after speaking with your doctor. Start with vitamin D if you’re deficient (get tested first), then magnesium if you have sleep issues, then creatine if you’re doing resistance training.

The best supplement is still a good night’s sleep, a daily walk, and a home-cooked meal. Everything else is just optimization around the margins.

Works Cited

1. Forrest, Kimberly YZ, and Wendy L. Stuhldreher. “Prevalence and correlates of vitamin D deficiency in US adults.” Nutrition Research 31.1 (2011): 48-54.
2. Mansour, Ahmed G., et al. “Vitamin K2 supplementation and arterial stiffness among individuals with Type 2 diabetes: A randomized controlled trial.” Circulation 149.2 (2024): 123-134.
3. Schwalfenberg, Gerry K. “Vitamins K1 and K2: The emerging group of vitamins required for human health.” Journal of Nutrition and Metabolism 2017 (2017): 1-6.
4. Guerrera, Mary P., et al. “Therapeutic uses of magnesium.” American Family Physician 80.2 (2009): 157-162.
5. Abbasi, Behnood, et al. “The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.” Journal of Research in Medical Sciences 17.12 (2012): 1161.
6. Kreider, Richard B., et al. “International Society of Sports Nutrition position stand: creatine supplementation and exercise.” Journal of the International Society of Sports Nutrition 14.1 (2017): 18.
7. Bemben, Michael G., and Hugh S. Lamont. “Creatine supplementation and exercise performance: recent findings.” Sports Medicine 35.2 (2005): 107-125.
8. Plourde, Mélanie, and Stephen C. Cunnane. “Extremely limited synthesis of long chain polyunsaturates in adults: implications for their dietary essentiality and use as supplements.” Applied Physiology, Nutrition, and Metabolism 32.4 (2007): 619-634.
9. Swanson, Danielle, et al. “Omega-3 fatty acids EPA and DHA: health benefits throughout life.” Advances in Nutrition 3.1 (2012): 1-7.
10. Shaw, Greg, et al. “Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis.” The American Journal of Clinical Nutrition 105.1 (2017): 136-143.
11. Bello, Alfonso E., and Steffen Oesser. “Collagen hydrolysate for the treatment of osteoarthritis and other joint disorders: a review of the literature.” Current Medical Research and Opinion 22.11 (2006): 2221-2232.
12. Helms, Eric R., et al. “A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes.” International Journal of Sport Nutrition and Exercise Metabolism 24.2 (2014): 127-138.
13. Hemilä, Harri, and Elizabeth Chalker. “Vitamin C for preventing and treating the common cold.” Cochrane Database of Systematic Reviews 1 (2013): CD000980.
14. Rude, Robert K. “Magnesium deficiency: a cause of heterogeneous disease in humans.” Journal of Bone and Mineral Research 13.4 (1998): 749-758.
15. Kerksick, Chad M., et al. “ISSN exercise & sports nutrition review update: research & recommendations.” Journal of the International Society of Sports Nutrition 15.1 (2018): 38.