What Vitamins Are Depleted by Aspirin? A Pharmacological Review

October 12, 2025 •

4 min read

A 2023 study found that daily low-dose aspirin increases the risk of anemia in older adults by approximately 20% [1.5.4]. This highlights a broader issue: understanding what vitamins are depleted by aspirin is crucial for the millions who use it daily for pain relief and cardiovascular protection [1.6.5, 1.6.2].

Quick Summary

Chronic aspirin use can interfere with the body's nutrient stores, primarily depleting Vitamin C, iron, folic acid, and zinc. This can lead to issues like increased bruising, fatigue, and anemia.

Key Points

Vitamin C Depletion: Aspirin increases the urinary excretion of Vitamin C and can impair its absorption, potentially weakening the immune system [1.3.2, 1.3.4].
Iron Deficiency Anemia: Long-term aspirin use is a major risk factor for iron-deficiency anemia, primarily due to chronic, low-level gastrointestinal bleeding [1.2.2, 1.5.3].
Folic Acid Loss: Aspirin can increase the loss of folic acid (Vitamin B9) through urine, which is crucial for cell growth and health [1.4.1].
Zinc Excretion: High doses of aspirin have been shown to increase the urinary excretion of the mineral zinc, which is important for immune function [1.9.1].
High-Risk Populations: Older adults and individuals with poor diets are particularly susceptible to nutrient depletion from chronic aspirin use [1.5.1, 1.6.3].
Mitigation is Key: The risks can be managed through a nutrient-rich diet and, under medical guidance, targeted supplementation [1.7.1, 1.6.3].
Consult a Doctor: Never stop or start supplements without first discussing them with your healthcare provider, especially when on long-term medication [1.7.1].

The Unseen Side Effect: Nutrient Depletion from Aspirin

Aspirin, or acetylsalicylic acid, is one of the most widely used medications globally for reducing pain, fever, and inflammation [1.6.2]. Many people also take a daily low dose for its blood-thinning properties to prevent heart attacks and strokes [1.6.5]. While its benefits are well-documented, a less-known consequence of long-term use is its ability to interfere with the body's absorption and retention of essential vitamins and minerals [1.2.1, 1.6.1].

This phenomenon, known as drug-induced nutrient depletion, occurs when a medication hinders the body's ability to digest, absorb, or utilize vital nutrients [1.7.1]. For aspirin users, this can lead to deficiencies that manifest in subtle but significant ways, impacting overall health and well-being. The primary nutrients of concern are Vitamin C, iron, folic acid, and zinc [1.2.1, 1.2.2].

The Primary Casualty: Vitamin C

The relationship between aspirin and Vitamin C is the most extensively studied interaction. Research shows that aspirin can significantly lower Vitamin C levels through several mechanisms [1.3.1]:

Increased Urinary Excretion: Aspirin has been shown to increase the rate at which Vitamin C is expelled from the body through urine [1.3.2, 1.7.2]. Since Vitamin C is water-soluble and cannot be stored by the body, this accelerated loss means less is available for crucial bodily functions [1.3.4].
Impaired Absorption: Aspirin may interfere with the active transport mechanisms that carry Vitamin C from the small intestine into the bloodstream [1.3.4]. Some research suggests that if aspirin is taken before Vitamin C, it can reduce the vitamin's absorption [1.3.5].
Gastric Mucosa Damage: Aspirin is known to cause irritation to the stomach lining [1.3.4]. The body may use available Vitamin C, a potent antioxidant, to help defend against and repair this damage, thereby depleting its reserves [1.3.1, 1.7.2].

Vitamin C is vital for immune function, skin health, and wound healing. A deficiency can lead to easy bruising, fatigue, and a weakened immune system. Individuals on long-term aspirin therapy may need to increase their intake to counteract these effects, with some sources recommending 100-200 mg per day [1.3.5, 1.2.2].

The Link to Anemia: Iron Depletion

A significant concern with chronic aspirin use, particularly in older adults, is the increased risk of iron-deficiency anemia [1.5.3, 1.6.3]. This occurs primarily through two pathways:

Gastrointestinal Bleeding: Aspirin's anti-platelet effect, while beneficial for preventing blood clots, increases the risk of bleeding. This can cause slow, chronic blood loss from the gastrointestinal (GI) tract, which may not be obvious (occult bleeding) [1.2.2, 1.6.3]. This steady loss of blood leads to a depletion of the body's iron stores.
Impaired Iron Stores: A major clinical trial (ASPREE) found that daily low-dose aspirin increased anemia risk by about 20% in healthy older adults, independent of major bleeding events [1.5.1, 1.5.4]. Participants taking aspirin showed a greater decline in ferritin, a protein that stores iron, suggesting that aspirin interferes with iron balance beyond just causing overt bleeding [1.5.4]. Recent studies propose that aspirin's metabolites can bind to iron, a process known as chelation, which may increase its excretion from the body [1.5.2, 1.6.2].

Symptoms of iron-deficiency anemia include fatigue, weakness, shortness of breath, and dizziness [1.5.3]. Regular monitoring of hemoglobin and ferritin levels may be necessary for older individuals on daily aspirin [1.5.4].

Impact on B Vitamins and More

Folic Acid (Vitamin B9): Evidence suggests that aspirin can also affect folic acid levels. It has been reported to increase the urinary loss of folic acid and reduce its blood levels, particularly in patients with rheumatoid arthritis who take high doses of aspirin [1.2.2, 1.4.1]. Folic acid is crucial for cell growth and DNA formation. Some doctors recommend supplementation for regular aspirin users [1.4.1].

Zinc: High doses of aspirin (around 3 grams per day) have been shown to decrease blood levels of zinc by increasing its excretion in the urine [1.2.2, 1.9.1]. Zinc is essential for immune function, wound healing, and protein synthesis.

Nutrient Depletion Comparison Table


Nutrient	Mechanism of Depletion by Aspirin	Common Symptoms of Deficiency	Excellent Food Sources
Vitamin C	Increases urinary excretion, impairs cellular absorption, and is used up to repair gastric damage [1.3.2, 1.3.4].	Fatigue, weakened immunity, easy bruising, slow wound healing.	Papaya, red peppers, black currants, oranges, broccoli [1.8.4].
Iron	Causes chronic, low-level gastrointestinal bleeding (occult blood loss) and may chelate iron, increasing excretion [1.2.2, 1.5.2].	Fatigue, weakness, pale skin, shortness of breath, dizziness [1.5.3].	Beef liver, oysters, spinach, lentils, fortified cereals [1.8.4, 1.7.1].
Folic Acid	Increases urinary excretion and may interfere with folate binding and metabolism [1.4.1, 1.4.3].	Fatigue, mouth sores, changes in skin or hair color, elevated homocysteine.	Beef liver, spinach, asparagus, fortified breakfast cereals [1.8.4].
Zinc	High doses increase urinary excretion [1.9.1].	Impaired immune function, hair loss, diarrhea, slow wound healing.	Oysters, beef shank, chicken, pork, yogurt [1.8.4].

Mitigating the Risks

For individuals on long-term aspirin therapy, awareness is the first step. It is essential not to stop prescribed medication without consulting a healthcare provider. Instead, consider the following strategies:

Dietary Focus: Prioritize consuming foods rich in the nutrients aspirin may deplete. A balanced diet full of fruits, vegetables, and lean proteins is fundamental [1.6.3].
Strategic Supplementation: Discuss supplementation with a doctor. They may recommend a multivitamin or specific supplements like Vitamin C, iron (only if a deficiency is confirmed by lab tests), or folic acid to counteract the depletion [1.2.2, 1.7.1].
Regular Monitoring: For those at high risk, especially older adults, periodic blood tests to check hemoglobin and ferritin levels can help detect anemia early [1.5.4, 1.6.3].

Conclusion

Aspirin remains a cornerstone of modern medicine, but its long-term use is not without consequence. The depletion of essential nutrients like Vitamin C and iron can lead to significant health issues, including an increased risk of anemia [1.5.5]. By understanding which vitamins and minerals are affected, individuals can work with their healthcare providers to develop strategies—through diet and targeted supplementation—to mitigate these risks and maintain optimal health while benefiting from aspirin's therapeutic effects.

For further reading on drug-nutrient interactions, consider resources from the Linus Pauling Institute.

Frequently Asked Questions

The most well-documented vitamin depleted by aspirin is Vitamin C. Aspirin increases its excretion through urine and can interfere with its absorption in the body [1.3.1, 1.3.2].

Yes, daily low-dose aspirin can lead to iron-deficiency anemia. It increases the risk of chronic gastrointestinal bleeding and may also interfere with the body's iron stores, as shown by lower ferritin levels in users [1.5.3, 1.5.4].

Aspirin primarily affects Folic Acid (Vitamin B9) by increasing its excretion [1.4.1]. There is also some weaker evidence suggesting an association between aspirin use and lower levels of Vitamin B12, possibly due to aspirin-induced stomach damage which is needed for B12 absorption [1.2.2].

You should consult your doctor before starting any supplements. They may recommend Vitamin C or folic acid. Iron supplements should only be taken if a deficiency is confirmed through a blood test, as excess iron can be harmful [1.2.2, 1.7.1].

Signs can include fatigue, weakness, and shortness of breath (from iron deficiency), or easy bruising and frequent colds (from Vitamin C deficiency) [1.5.3].

To counteract depletion, focus on foods rich in Vitamin C (citrus fruits, peppers), iron (lean red meat, spinach, lentils), and folic acid (leafy greens, asparagus, fortified cereals) [1.8.4].

Aspirin primarily depletes the mineral iron, which can lead to anemia [1.6.1]. High doses may also increase the excretion of zinc and potassium [1.2.1, 1.9.1].