Do I really need supplements if I eat a healthy diet?

You may not need many supplements if you eat a high-quality diet, but most adults still have 1 or 2 true gaps. Vitamin D is low in most people who live north of Atlanta because of weak winter sunlight. Magnesium and omega-3s are commonly low even in good eaters. We test before we recommend.

Are multivitamins worth taking?

Most generic multivitamins are not worth taking because the doses are too low for the actual deficiencies and too high for nutrients you do not need. We prefer targeted single-nutrient supplements at clinical doses, chosen from your lab data. Some patients with restricted diets do benefit from a quality multivitamin.

What is the difference between RBC magnesium and serum magnesium?

Serum magnesium is what is floating in your blood at that moment, and your body works hard to keep it stable even when stores are low. RBC magnesium reflects what is inside your red blood cells, a much better mirror of long-term tissue stores. We use RBC magnesium because serum looks falsely normal in most patients.

Is too much vitamin D dangerous?

Yes, very high vitamin D over time can be harmful, particularly when paired with high calcium. We aim for a 25-hydroxy vitamin D level of 50 to 80 ng/mL. Doses of 2,000 to 5,000 IU per day are typical. We retest every 3 to 6 months until levels stabilize.

Should I take a B-complex or just B12?

That depends on what your labs show. If only B12 is low, we treat B12. If you are on metformin, restrictive diets, or have a methylation issue, a B-complex with methylated B12 and folate is often a better fit. We try not to use shotgun B-complex doses without a reason.

Can supplements interact with prescription medications?

Yes, supplements can absolutely interact with prescription medications. Common examples include St. John's Wort with antidepressants, vitamin K with warfarin, and high-dose niacin with statins. We always review the full medication list before adding supplements, and we want to know about every bottle in your cabinet.

How can I tell if a supplement brand is trustworthy?

Look for third-party testing through groups like USP, NSF, or ConsumerLab. Avoid proprietary blends, which hide the actual doses behind a marketing term. The ingredient list should be short, the doses clear, and the company should be transparent about sourcing.

Are gummies a reasonable form of supplements?

Gummies are usually the worst form for most nutrients. They tend to be low-dose, mixed with sugar, and not the right vehicle for fat-soluble vitamins like D or K. We use them sparingly and only when patients cannot tolerate other forms.

Why does ferritin matter more than serum iron for iron status?

Ferritin is the protein that stores iron in your body. Serum iron fluctuates with the meal you just ate, but ferritin reflects long-term stores. We aim for a ferritin between 50 and 150 ng/mL for most patients. Many women with chronic fatigue have a ferritin under 30, which is "normal" by lab cutoffs but functionally low.

What is methylation and why does it matter for B vitamins?

Methylation is a biochemical process where your body adds a methyl group (a small chemical tag) to molecules to switch them on or off. It is essential for detox, neurotransmitter production, and DNA repair. People with MTHFR gene variants may need methylated B12 and folate instead of the standard cyanocobalamin and folic acid forms.

How does the gut microbiome affect nutrient absorption?

The gut microbiome (the trillions of bacteria in your intestines) helps produce vitamin K, some B vitamins, and short-chain fatty acids. A disrupted microbiome from antibiotics, alcohol, or chronic inflammation can lower absorption of many nutrients. We support it with fiber, fermented foods, and selective probiotics, not with expensive boutique stool tests for every patient.

Are omega-3 supplements worth it?

For most adults, yes. The American diet is heavy in omega-6 fats and light on omega-3s, which drives inflammation. We measure the omega-3 index (the percentage of EPA and DHA in your red blood cell membranes). A target of 8 to 12% is associated with the lowest cardiovascular risk in observational studies.

Should I be taking creatine even if I do not lift?

Creatine has strong evidence for muscle, recovery, and even cognitive function in some studies. 3 to 5 grams a day of creatine monohydrate is safe, cheap, and useful for most active adults. The kidney concerns in healthy people are largely overblown.

What is the role of magnesium in sleep and stress?

Magnesium activates the parasympathetic nervous system (the rest-and-digest side) and supports GABA receptors. Most adults are functionally low. Forms vary by goal. Glycinate is gentle and good for sleep, threonate crosses into the brain, and citrate is fine but can be laxative at higher doses.

How do I think about adaptogens like ashwagandha?

Adaptogens are herbs traditionally used to help the body manage stress. Ashwagandha has the best evidence, with several small studies showing modest cortisol reductions. We use it as a tool, not a cure. We avoid it in patients with hyperthyroidism or who are on immunosuppressants.

Can supplements actually cause harm?

Yes, supplements can absolutely cause harm. High-dose vitamin B6 can cause neuropathy. High-dose iron can damage the gut. Hepatotoxic herbs like green tea extract and turmeric have been linked to liver injury in some patients. Quality, dose, and need all matter.

What about NAD+ precursors like NR and NMN?

NAD+ precursors like nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are popular for longevity. The animal data are interesting, but human outcome data are still early. We discuss them with patients who want to invest in emerging tools, while keeping expectations honest.

How do GLP-1 medications change supplement needs?

GLP-1 medications like semaglutide and tirzepatide reduce appetite and food volume, which can lead to lower protein and micronutrient intake. We monitor B12, iron, and protein intake closely in patients on GLP-1s. We also push protein supplementation if total intake drops below target.

Is there a role for IV vitamins?

IV vitamins have a place in select cases, like proven malabsorption or specific deficiencies. For most healthy patients, oral or sublingual forms are cheaper, safer, and equally effective. We do not run a "drip bar." We use IV when the lab data justify it.

How long should I take a supplement before checking if it works?

Most micronutrient supplements need 8 to 12 weeks to change labs and symptoms. Iron and vitamin D often need 12 to 16 weeks. Adaptogens and probiotics should be reassessed at 6 to 8 weeks. We retest, look at the trend, then keep, adjust, or stop.

Can supplements replace lifestyle?

No, supplements cannot replace sleep, training, protein, and stress management. They can fill specific gaps that nutrition and lifestyle alone cannot fix. The best results come when supplements support an already-strong foundation, not when they try to compensate for a missing one.

How often should I retest my micronutrient panel?

For most patients, we run an advanced micronutrient panel at baseline and then every 6 to 12 months. If we are actively correcting a deficiency, we recheck at 3 months. Once stable, we move to annual labs.

Do I really need supplements if I eat a healthy diet?

You may not need many supplements if you eat a high-quality diet, but most adults still have 1 or 2 true gaps. Vitamin D is low in most people who live north of Atlanta because of weak winter sunlight. Magnesium and omega-3s are commonly low even in good eaters. We test before we recommend.

Are multivitamins worth taking?

Most generic multivitamins are not worth taking because the doses are too low for the actual deficiencies and too high for nutrients you do not need. We prefer targeted single-nutrient supplements at clinical doses, chosen from your lab data. Some patients with restricted diets do benefit from a quality multivitamin.

What is the difference between RBC magnesium and serum magnesium?

Serum magnesium is what is floating in your blood at that moment, and your body works hard to keep it stable even when stores are low. RBC magnesium reflects what is inside your red blood cells, a much better mirror of long-term tissue stores. We use RBC magnesium because serum looks falsely normal in most patients.

Is too much vitamin D dangerous?

Yes, very high vitamin D over time can be harmful, particularly when paired with high calcium. We aim for a 25-hydroxy vitamin D level of 50 to 80 ng/mL. Doses of 2,000 to 5,000 IU per day are typical. We retest every 3 to 6 months until levels stabilize.

Should I take a B-complex or just B12?

That depends on what your labs show. If only B12 is low, we treat B12. If you are on metformin, restrictive diets, or have a methylation issue, a B-complex with methylated B12 and folate is often a better fit. We try not to use shotgun B-complex doses without a reason.

Can supplements interact with prescription medications?

Yes, supplements can absolutely interact with prescription medications. Common examples include St. John's Wort with antidepressants, vitamin K with warfarin, and high-dose niacin with statins. We always review the full medication list before adding supplements, and we want to know about every bottle in your cabinet.

How can I tell if a supplement brand is trustworthy?

Look for third-party testing through groups like USP, NSF, or ConsumerLab. Avoid proprietary blends, which hide the actual doses behind a marketing term. The ingredient list should be short, the doses clear, and the company should be transparent about sourcing.

Are gummies a reasonable form of supplements?

Gummies are usually the worst form for most nutrients. They tend to be low-dose, mixed with sugar, and not the right vehicle for fat-soluble vitamins like D or K. We use them sparingly and only when patients cannot tolerate other forms.

Why does ferritin matter more than serum iron for iron status?

Ferritin is the protein that stores iron in your body. Serum iron fluctuates with the meal you just ate, but ferritin reflects long-term stores. We aim for a ferritin between 50 and 150 ng/mL for most patients. Many women with chronic fatigue have a ferritin under 30, which is "normal" by lab cutoffs but functionally low.

What is methylation and why does it matter for B vitamins?

Methylation is a biochemical process where your body adds a methyl group (a small chemical tag) to molecules to switch them on or off. It is essential for detox, neurotransmitter production, and DNA repair. People with MTHFR gene variants may need methylated B12 and folate instead of the standard cyanocobalamin and folic acid forms.

How does the gut microbiome affect nutrient absorption?

The gut microbiome (the trillions of bacteria in your intestines) helps produce vitamin K, some B vitamins, and short-chain fatty acids. A disrupted microbiome from antibiotics, alcohol, or chronic inflammation can lower absorption of many nutrients. We support it with fiber, fermented foods, and selective probiotics, not with expensive boutique stool tests for every patient.

Are omega-3 supplements worth it?

For most adults, yes. The American diet is heavy in omega-6 fats and light on omega-3s, which drives inflammation. We measure the omega-3 index (the percentage of EPA and DHA in your red blood cell membranes). A target of 8 to 12% is associated with the lowest cardiovascular risk in observational studies.

Should I be taking creatine even if I do not lift?

Creatine has strong evidence for muscle, recovery, and even cognitive function in some studies. 3 to 5 grams a day of creatine monohydrate is safe, cheap, and useful for most active adults. The kidney concerns in healthy people are largely overblown.

What is the role of magnesium in sleep and stress?

Magnesium activates the parasympathetic nervous system (the rest-and-digest side) and supports GABA receptors. Most adults are functionally low. Forms vary by goal. Glycinate is gentle and good for sleep, threonate crosses into the brain, and citrate is fine but can be laxative at higher doses.

How do I think about adaptogens like ashwagandha?

Adaptogens are herbs traditionally used to help the body manage stress. Ashwagandha has the best evidence, with several small studies showing modest cortisol reductions. We use it as a tool, not a cure. We avoid it in patients with hyperthyroidism or who are on immunosuppressants.

Can supplements actually cause harm?

Yes, supplements can absolutely cause harm. High-dose vitamin B6 can cause neuropathy. High-dose iron can damage the gut. Hepatotoxic herbs like green tea extract and turmeric have been linked to liver injury in some patients. Quality, dose, and need all matter.

What about NAD+ precursors like NR and NMN?

NAD+ precursors like nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are popular for longevity. The animal data are interesting, but human outcome data are still early. We discuss them with patients who want to invest in emerging tools, while keeping expectations honest.

How do GLP-1 medications change supplement needs?

GLP-1 medications like semaglutide and tirzepatide reduce appetite and food volume, which can lead to lower protein and micronutrient intake. We monitor B12, iron, and protein intake closely in patients on GLP-1s. We also push protein supplementation if total intake drops below target.

Is there a role for IV vitamins?

IV vitamins have a place in select cases, like proven malabsorption or specific deficiencies. For most healthy patients, oral or sublingual forms are cheaper, safer, and equally effective. We do not run a "drip bar." We use IV when the lab data justify it.

How long should I take a supplement before checking if it works?

Most micronutrient supplements need 8 to 12 weeks to change labs and symptoms. Iron and vitamin D often need 12 to 16 weeks. Adaptogens and probiotics should be reassessed at 6 to 8 weeks. We retest, look at the trend, then keep, adjust, or stop.

Can supplements replace lifestyle?

No, supplements cannot replace sleep, training, protein, and stress management. They can fill specific gaps that nutrition and lifestyle alone cannot fix. The best results come when supplements support an already-strong foundation, not when they try to compensate for a missing one.

How often should I retest my micronutrient panel?

For most patients, we run an advanced micronutrient panel at baseline and then every 6 to 12 months. If we are actively correcting a deficiency, we recheck at 3 months. Once stable, we move to annual labs.

The New York Times is Right (and Wrong) About Supplements

TL;DR30-second take

The answer is not 'eat more spinach' or 'take more pills.' Both miss the point. We measure red blood cell magnesium, ferritin, vitamin D, B12, and a few other markers, then build a small, targeted supplement plan around your real labs. Most patients end up taking fewer supplements, not more, and feel better.

Why "Supplements vs. Real Food" Is a False Choice

The New York Times recently published a piece titled "Do You Need These Popular Supplements?" questioning the value of everything from magnesium to multivitamins. The core argument was familiar. Just eat a balanced diet, and you do not need pills.

Real food plate with salmon, spinach, and beans Photographs by Ghazalle Badiozamani for The New York Times

Meanwhile your favorite health influencer is selling a 20-pill stack for longevity.

Supplements plate Photographs by Ghazalle Badiozamani for The New York Times

The media loves this fight. It frames health as a binary choice between "naturalist" and "biohacker." One side says nature provides everything. The other side says science can optimize everything. Both sides miss the point.

In my practice of Medicine 3.0, we do not work from philosophy. We work from data. The right question is not "do people need supplements?" It is "do you need supplements, and which ones at what dose?"

A Tale of Two Patients

This morning I was reviewing charts for 2 very different patients. Their stories show why generic advice fails.

The "Unlimited" CEO

The first was a CEO of a heavy industries company. He has every resource imaginable, including a personal trainer, a private chef, and unlimited access to supplements. He was taking everything. He had a stack for energy, a stack for recovery, and a stack for sleep.

His labs told a different story. His liver enzymes were elevated from processing so many compounds. His B6 levels were actually toxic, a common side effect of blind supplementation. He was over-supplemented and under-nourished at the same time.

The "Healthy" Realtor

The second patient was a self-employed realtor. She did not have a trainer, but she had symptoms. Fatigue, brain fog, brittle nails. She read online that she needed "adrenal support" and "thyroid boosters," so she built a significant regimen around her symptoms.

Her labs were a different picture. She was severely iron-deficient and had a vitamin D level of 12 ng/mL (optimal is 50 to 80). No amount of "adrenal support" was going to fix an iron deficiency.

The fix. Once we looked at the bloodwork, we simplified both regimens to 3 key, targeted interventions each. For the CEO, we cut 90% of the noise and focused on absorption. For the realtor, we treated her specific deficiencies. Both patients felt better within weeks. Not because we added more, but because we got precise.

Why "Just Eat Real Food" Is Often Lazy Advice

The "just eat real food" message has truth in it. In an ideal world, your plate would carry everything you need. We do not live in that world.

Soil depletion. Regenerative agriculture researchers have shown the nutrient density of topsoil has dropped significantly over the last 50 years. An orange today likely has less vitamin C than an orange in 1950.
Malabsorption. As we age, stomach acid weakens. You may be eating B12 in your steak without absorbing much of it.
Medications. Common drugs like proton pump inhibitors (PPIs for acid reflux) and metformin (for diabetes) actively deplete nutrients like magnesium and B12.

Telling someone on a diuretic to "just eat spinach" for magnesium, while their kidneys are flushing it out, is not helpful. It is clinically incomplete.

Fishtown Medicine

A 90-minute conversation with Dr. Ash. A written plan you can actually follow.

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How Does Fishtown Medicine Approach Supplements?

The Fishtown Medicine approach to supplements rejects guessing in either direction. We measure first, then choose a small, targeted plan based on your labs.

We use advanced micronutrient testing. Instead of asking "do I need magnesium?", we measure your red blood cell (RBC) magnesium, which reflects intracellular stores. We look at ferritin, the protein that stores iron, not just serum iron. We measure 25-hydroxy vitamin D. We check B12, folate, and the B-vitamin pathway markers like methylmalonic acid (MMA) when needed.

Only then do we recommend a supplement.

"I do not care what the average person needs. You are not the average person. You are N=1. Lets look at your dashboard." Dr. Ash

Guidance from the Clinic

In my experience, most patients on 15 to 20 supplements are spending hundreds of dollars a month and getting marginal benefit. The same patients, on 3 to 5 well-chosen supplements at clinical doses, almost always feel better within a few weeks. Less, but better, wins.

I have also seen the other extreme. Patients who refuse all supplementation on principle, even when their vitamin D is 18 or their ferritin is 12. Principle does not raise iron stores. Numbers do.

Actionable Steps in Philly

Test, then choose. Pair good food with a small, targeted plan.

Get the right baseline labs. Ask for ferritin, RBC magnesium, vitamin D (25-OH), B12, folate, omega-3 index, and a basic metabolic panel.
Audit your current stack. Bring every bottle to your visit, including powders. We can usually cut the list by half without losing benefit.
Pick whole-food sources first where possible. Then fill the gaps with high-quality, third-party-tested supplements at clinical doses.

Book Your Warm Invitation Call Here

Key Takeaways

Test, do not guess. Before you buy another bottle from an influencer or throw all your vitamins out because of a news article, get the right labs.
Symptoms lie. Fatigue can be low iron, low B12, low thyroid, or low testosterone. You cannot feel the difference. You have to measure it.
Quality over quantity. Most people taking 20 supplements actually need 3 to 5 specific ones at the right dose.
Food first, but not food only. Eat the highest quality food you can afford and use data to fill the gaps modern life creates.

Scientific References

Holick MF. "The vitamin D deficiency pandemic." Reviews in Endocrine and Metabolic Disorders. 2017.
DiNicolantonio JJ, et al. "Subclinical magnesium deficiency: a principal driver of cardiovascular disease." Open Heart. 2018.
Pasiakos SM, et al. "Effects of protein supplements on muscle damage, soreness and recovery of muscle function and physical performance: A systematic review." Sports Med. 2014.
Brown RB. "Vitamin B6 toxicity revisited." Mayo Clin Proc. 2020.
Dwyer JT, et al. "Multivitamin/mineral supplements: rationale and safety." Nutrition. 2018.

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2418 E York St, Philadelphia, PA 19125(267) 360-7927 hello@fishtownmedicine.comHSA/FSA Eligible

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