What your medication might be quietly depleting

If you take a daily prescription, there is a reasonable chance it affects more than the condition it was prescribed for. Some medications can lower specific nutrient levels over time. Others are associated with nutrient changes, but the clinical significance is less certain.

That distinction matters. Metformin and vitamin B12 is not the same kind of evidence as oral contraceptives and folate. Long-term PPI use and magnesium is not the same claim as "PPIs deplete calcium." A useful medication-depletion guide should help you ask better questions, not make every association sound equally proven.

This guide walks through five common medication classes and the nutrients most often discussed with each. The point is not to scare you off your prescription. The point is to know what to ask your doctor or pharmacist about, and to think about supplements in the context of medication, duration, symptoms, labs, and evidence quality.

A note on what this is and isn't

If you are taking one of these medications long-term, a practical way to start the conversation is: "I read that this medication can affect [nutrient]. Based on my dose, duration, symptoms, and risk factors, should we check anything or change my supplement plan?" For the broader framing of how we grade evidence, see our methodology page.

Do statins deplete CoQ10?

Statins (atorvastatin, simvastatin, rosuvastatin, pravastatin) work by inhibiting HMG-CoA reductase, an enzyme upstream of cholesterol production. That same pathway also contributes to the body's production of coenzyme Q10, a molecule involved in cellular energy production.

What is established. Statins can lower CoQ10 concentrations. That biochemical effect is plausible and documented. Established

What is not established. Lower CoQ10 does not automatically mean CoQ10 supplementation reliably fixes statin-associated muscle symptoms. NCCIH summarizes the clinical evidence as not supporting CoQ10 for statin-related muscle pain overall, even though individual trials and meta-analyses have not all pointed the same way.

That distinction is central: a documented biochemical effect does not automatically mean a supplement has a proven clinical benefit.

What to ask about. If you have muscle aches, weakness, or exercise intolerance after starting or increasing a statin, ask your clinician to evaluate the symptom pattern and rule out other causes. CoQ10 is sometimes discussed as a low-risk trial, often around 100-200 mg/day with food, but it is not routine statin care. For the full evidence breakdown, see our full review of statins and CoQ10.

Does metformin lower vitamin B12?

Metformin is one of the strongest medication-nutrient examples in this guide. It has a well-documented effect on vitamin B12 status, likely involving impaired calcium-dependent uptake of the intrinsic-factor-B12 complex in the small intestine. Long-term users develop measurable B12 deficiency more often than people not taking metformin.

Why it matters. B12 deficiency can present as fatigue, neuropathy (tingling in the feet and hands), cognitive fog, and in advanced cases anemia. The overlap with diabetic neuropathy is clinically important: numbness or tingling may be attributed to diabetes itself when B12 should also be checked.

What to ask about. The American Diabetes Association's 2026 Standards recommend considering periodic B12 assessment in people receiving long-term metformin therapy, especially when anemia or peripheral neuropathy is present. If you have taken metformin for years and have not had B12 checked recently, that is a specific, evidence-aligned conversation.

Do PPIs cause magnesium and B12 deficiency?

Proton pump inhibitors (PPIs) like omeprazole, pantoprazole, esomeprazole, and lansoprazole suppress stomach acid production. That is why they work for reflux, ulcers, and esophageal irritation. With prolonged use, they can also affect nutrients that depend on gastric acidity or intestinal handling.

Magnesium is the strongest claim. Current PPI labeling recognizes hypomagnesemia with prolonged PPI use. Cases have occurred after at least three months, but most were reported after a year or more. Clinicians may consider magnesium monitoring before and during prolonged therapy, especially when a person also takes digoxin or drugs that can lower magnesium, such as diuretics. Established

B12 is reasonable but more contextual. Acid helps release B12 from food protein, so prolonged acid suppression can contribute to lower B12 status in some people, especially with other risk factors.

Calcium needs softer language. Long-term or high-dose PPI therapy has been associated with fracture concerns and altered calcium handling, but that is not the same as saying PPIs straightforwardly "deplete calcium." If calcium is discussed, it should be framed around bone risk, dietary intake, calcium form, and whether the PPI is still needed.

What to ask about. Ask whether you still need the PPI at the current dose and duration, and whether magnesium or B12 testing makes sense based on your symptoms and risk factors.

What do diuretics deplete?

"Diuretics" is too broad to treat as one uniform nutrient-depletion category. Loop diuretics (furosemide, torsemide, bumetanide) and thiazide or thiazide-like diuretics (hydrochlorothiazide, chlorthalidone) both increase urinary fluid and electrolyte losses, but their patterns and monitoring needs are not identical.

Loop and thiazide diuretics: potassium and magnesium. Potassium and magnesium abnormalities are the most clinically important nutrient-related issues here. Low potassium can affect heart rhythm. Magnesium matters for muscle, nerve, and cardiac function, and it can interact with potassium balance. Established

Chronic high-dose loop diuretics: possible thiamine. Thiamine (vitamin B1) depletion is most often discussed in people with heart failure receiving chronic or high-dose loop diuretics, especially furosemide. The literature describes variable rates, so this is better framed as a conditional risk than as a universal diuretic effect. Conditional

What to ask about. Ask about medication-specific monitoring: potassium, kidney function, and magnesium when appropriate. Do not start potassium or high-dose magnesium on your own if you take a diuretic.

Does birth control deplete vitamins?

Combined oral contraceptives (the "pill") have been studied for possible effects on folate, vitamin B6, vitamin B12, and other micronutrients. This is the section where evidence language matters most.

Older studies often reported lower nutrient levels in oral-contraceptive users, but many were conducted when estrogen doses were higher than in current products. A detailed review of modern oral contraceptives concluded that available data did not support a clear negative effect on folate status, while the signal for vitamin B6 was more credible. Functional B12 status was not clearly affected. Other reviews have reported broader nutrient changes, which is exactly why this should be treated as mixed evidence rather than a straightforward depletion relationship. Mixed

Why folate still matters. People who could become pregnant should meet recommended folate intake regardless of contraceptive use, because adequate folate before and early in pregnancy lowers neural tube defect risk. That is a pregnancy-prevention-and-planning point, not proof that modern oral contraceptives meaningfully deplete folate.

What to ask about. There is no standard "birth-control nutrient-depletion panel." If you have fatigue, mood changes, headaches, cravings, dietary restrictions, heavy bleeding, or pregnancy plans, discuss targeted testing or supplementation with your clinician.

What should you do about medication nutrient depletion?

Three takeaways:

1. Ask for medication-specific monitoring, not a generic micronutrient panel. Metformin points most clearly to B12. Long-term or higher-risk PPI use points most clearly to magnesium, sometimes B12. Diuretics point to potassium, kidney function, and magnesium when appropriate. Statins point to evaluating muscle symptoms, not routine CoQ10 testing. Oral contraceptives do not imply a standard nutrient-depletion lab panel.

2. Do not self-supplement potassium or aggressively self-supplement magnesium if you are on a diuretic. Those are clinician-guided decisions because the wrong dose can create cardiac risk.

3. Treat supplements as evidence-specific tools, not automatic fixes. B12 replacement for documented low B12 on metformin is a different decision than trying CoQ10 for statin muscle symptoms or taking a B-complex because you use oral contraception. The better question is: "What is the evidence level, what is my risk, and what would we measure?"

This is the kind of cross-checking PharmaGuide does when you add a medication to your stack: it surfaces documented depletion patterns, evidence level, and clinician discussion points. If you are on a GLP-1 medication, the nutrient picture is different; see our GLP-1 nutrient gap guide.

Frequently asked questions

Which medications cause nutrient depletion?

The most established examples in this guide are metformin and vitamin B12, prolonged PPI use and magnesium, and loop/thiazide diuretics with potassium and magnesium abnormalities. Statins can lower CoQ10 concentrations, but the clinical benefit of supplementation is uncertain. Oral contraceptive nutrient effects are mixed and should not be presented as a simple depletion claim.

How do I know if my medication is depleting a nutrient?

Ask your clinician for medication-specific monitoring. Examples include B12 for long-term metformin use, magnesium for prolonged or higher-risk PPI use, and potassium/kidney function for diuretics. Symptoms can guide the conversation, but labs and clinical context matter.

Can I just take a multivitamin to cover medication depletion?

A multivitamin can help as a general baseline, but it does not solve every medication-specific issue. It will not meaningfully address potassium replacement, may not contain CoQ10, and may not correct a true B12 deficiency. Targeted decisions based on risk, symptoms, and labs are more defensible than a blanket approach.

Should I stop my medication if it is causing a deficiency?

No. The medication is treating a condition that matters. The usual response is to monitor, confirm, and address the nutrient issue while preserving appropriate prescription treatment. Discuss any concerns with your prescriber before changing or stopping a medication.

Sources

• American Diabetes Association — Standards of Care in Diabetes
• NIH NCCIH — Coenzyme Q10
• NIH Office of Dietary Supplements — Vitamin B12
• NIH Office of Dietary Supplements — Magnesium
• NIH Office of Dietary Supplements — Folate
• DailyMed — omeprazole labeling
• DailyMed — FDA-curated drug labeling
• Wilson SMC, et al. (2011). Oral contraceptive use: impact on folate, vitamin B6, and vitamin B12 status. Nutrition Reviews.
• Katta N, et al. (2016). Does long-term furosemide therapy cause thiamine deficiency in patients with heart failure?. American Journal of Medicine.