November 2026
It’s not uncommon to wonder if you’re getting the recommended daily amount of every vitamin and mineral. To prevent nutrient deficiencies, which occur when your body has too little of a certain vitamin or mineral, eat a nutritious, varied diet or include supplements if your eating habits fall short.
The CDC’s most recent National Nutrition Report found that Americans have generally improved their intake of important vitamins and minerals compared to previous decades. This is mainly thanks to food fortification (like adding folic acid to enriched grains) and supplements. But that doesn’t mean the problem of nutrient deficiencies has gone away.
Learn more about causes of nutrient deficiencies — and how to recognize if you may have one.
What causes nutrient deficiencies?
A variety of factors — including a poor diet, certain health conditions
(such as kidney disease, celiac disease, and inflammatory bowel disease), and some medications — can deplete your body of certain nutrients. Here are some common prescriptions and over-the-counter drugs that can cause nutrient depletions.
Oral contraceptives
Research shows that women who take estrogen-containing oral contraceptives tend to have lower blood levels of vitamins B2, B6, B9 (folate), C, and E, along with the minerals magnesium, selenium, and zinc, compared to women who don’t. While most women who eat a balanced diet will typically only see a modest drop in blood levels (rather than true deficiencies), it’s still worth being aware of.
Antibiotics
Antibiotics — including penicillin, macrolides, and tetracyclines — are critical for fighting bacterial infections like strep throat and urinary tract infections. But antibiotics also kill off some of the good bacteria in your gut. And since some of those good bacteria produce vitamin K, taking antibiotics for more than a few weeks can reduce the amount your body has available. People using antibiotics for a longer period may want to eat more foods rich in vitamin K or take a vitamin K supplement. But if you take a blood thinner (like warfarin), talk to your doctor or pharmacist first; vitamin K (whether from food or supplements) can interfere with how this medication works.
Proton pump inhibitors (used for acid reflux and stomach ulcers)
Available both OTC (Prilosec, Nexium, Prevacid) and by prescription (Protonix, AcipHex, Dexilant), PPIs fight acid reflux by reducing the amount of acid made by glands in your stomach lining. A systematic review published in 2025 found that long-term use of PPIs can lower levels of vitamin B12 and calcium. An earlier review also linked them to lower levels of iron, magnesium, and vitamin C. The risk is relatively low for most people but higher for older or malnourished adults.
Metformin (used to manage type 2 diabetes)
Metformin is one of the most commonly prescribed medications for type 2 diabetes. Over time, it can interfere with your body’s ability to absorb vitamin B12, and long-term use is linked to lower B12 levels. Low B12 can cause fatigue, weakness, numbness, and anemia. That’s why many doctors recommend periodic B12 checks for people on metformin long-term.
Signs of nutrient deficiency
Different nutrient deficiencies have different symptoms, but here are some common ones to look out for. Be sure to tell your doctor if you’re experiencing them.
Hair loss
If you’re noticing more hair than usual in your shower drain or on your pillow, it could be a sign of iron deficiency. Your doctor can check your iron level with a simple blood test. If it’s low, they can recommend the right type of iron for you — different forms absorb differently, and some cause more side effects than others.
Bleeding gums or slow wound healing
Vitamin C helps your body make collagen, a protein that supports healthy skin, blood vessels, and gums. When you’re low on it, cuts and scrapes may be slow to heal, and your gums may bleed more easily. You can boost your vitamin C by eating more fruits and vegetables —like citrus, bell peppers, strawberries, and broccoli — or by taking a multivitamin.
Fatigue and muscle weakness
Occasional tiredness is normal, but if you’re constantly feeling fatigued and weak, it could be a sign that you’re deficient in certain nutrients, including vitamin D or iron. Because it’s hard to get adequate vitamin D through diet alone, your doctor may recommend taking a supplement.
Easy bruising
Although some people bruise easily because their blood vessels are naturally more fragile, this could be a symptom of nutrient deficiency for others. Easy bruising could be a sign that you’re deficient in vitamin C.
What to do if you suspect a nutrient deficiency
If you suspect a nutrient deficiency, don’t self-diagnose or start supplements on your own. The symptoms of nutrient deficiencies are vague and easy to misread, and more isn’t always better. Taking vitamins and minerals you don’t need can cause them to build up to harmful levels or interfere with your medications.
Instead, talk to your doctor. A simple blood test can see whether you’re actually low in any nutrients. That way, any supplement or diet change is based on actual need.
