Can Citracal cause nausea?: Understanding Calcium Citrate's Side Effects

October 9, 2025 •

4 min read

According to studies, nausea is a recognized, though often mild, side effect associated with calcium citrate supplements like Citracal. While typically less severe than other forms of calcium, understanding why Can Citracal cause nausea? is key to managing your supplement regimen effectively and comfortably.

Quick Summary

Calcium citrate supplements can cause nausea in some individuals, though it is usually a mild side effect. Taking supplements with food or adjusting your dosing schedule can often mitigate this issue. Severe nausea may indicate an excessive calcium intake, requiring medical attention.

Key Points

Common Side Effect: Nausea is a known side effect of Citracal (calcium citrate), though it is generally considered milder than with other calcium forms like calcium carbonate.
Take With Food: Taking your dose of Citracal with a meal can significantly reduce the likelihood of experiencing nausea.
Split Doses: If a single large dose causes stomach upset, breaking your daily intake into smaller, more frequent doses may help.
Consider Timing: Some individuals find that taking their supplement before bedtime minimizes daytime nausea.
Watch for Overdose: Severe nausea and vomiting can be signs of hypercalcemia, a serious condition caused by excessive calcium intake.
Consult a Doctor: Persistent or severe nausea should be discussed with a healthcare provider to explore alternatives or rule out other issues.

The Link Between Citracal and Nausea

Citracal is a brand name for a calcium citrate supplement, an over-the-counter medication used to boost calcium intake. While calcium is vital for bone health and other bodily functions, introducing a concentrated dose can sometimes disrupt the gastrointestinal (GI) tract. Nausea, alongside other GI complaints like gas, bloating, and constipation, is a possible side effect of calcium citrate, especially in sensitive individuals. Although calcium citrate is often promoted as being gentler on the stomach than its counterpart, calcium carbonate, it does not eliminate the risk of stomach upset entirely.

How Calcium Supplements Affect the Stomach

Calcium supplements can affect the stomach in several ways, potentially leading to nausea. For some people, the sheer size of the tablet can be hard to swallow or digest, triggering a gag reflex or a feeling of discomfort. The supplement's binding agents, used to hold the tablet together, can also contribute to irritation of the stomach lining. The presence of calcium itself can influence the digestive process. In high concentrations, calcium can slow down the motility of the digestive tract, leading to a feeling of fullness and constipation, which can be accompanied by nausea. Furthermore, taking a calcium supplement, particularly a large dose, on an empty stomach can trigger irritation by stimulating gastric acid production, which can cause discomfort, heartburn, and nausea.

Factors That Increase Nausea Risk

Several factors can increase the likelihood of experiencing nausea when taking Citracal. One of the most significant is the amount of calcium consumed at one time. The body's absorption efficiency of calcium decreases as the dose increases. Taking a large dose of calcium citrate all at once is more likely to overwhelm the digestive system and cause a reaction than splitting the dose throughout the day.

High Dosage and Hypercalcemia

Severe or persistent nausea, especially when accompanied by vomiting, increased thirst or urination, muscle weakness, and fatigue, could be a sign of hypercalcemia, or excessively high levels of calcium in the blood. This condition is often caused by taking too much calcium and requires immediate medical attention. It is critical to adhere to the recommended dosage of any supplement and consult a healthcare provider if severe symptoms arise.

Empty Stomach vs. Full Stomach

While calcium citrate can technically be taken with or without food, taking it with a meal is a common recommendation to minimize GI side effects. Food provides a buffer in the stomach, which can help neutralize gastric acids and reduce the supplement's irritating effects. However, if your nausea is caused by the slow digestion of calcium, taking it with food might not fully eliminate the problem. Trying different timings, such as before bedtime, can sometimes help individuals who experience persistent nausea during the day.

Managing and Preventing Nausea from Citracal

If you find yourself experiencing nausea after taking Citracal, there are several practical steps you can take to manage and prevent it. Here are some strategies:

Take with Food: The simplest and most effective approach is to take your supplement with a meal or a small snack.
Divide the Dose: Instead of taking your full daily dose at once, split it into smaller, more frequent doses throughout the day. This allows your body to process the calcium more efficiently.
Change the Timing: Try taking your supplement at a different time of day, such as with dinner or before bed, to see if it lessens the impact on your stomach.
Consider a Different Formulation: If tablets are causing irritation, consider switching to a chewable, liquid, or gummy form of calcium, as these can sometimes be gentler on the digestive system.
Stay Hydrated: Drinking plenty of water can help with overall digestion and may alleviate some GI discomfort.
Avoid High-Dose Combinations: Ensure you are not taking multiple supplements or medications that contain calcium, as this can increase the risk of an overdose and related side effects.
Consult a Professional: If nausea persists, it's best to consult a pharmacist or doctor to discuss your options and rule out underlying issues.

Calcium Citrate vs. Calcium Carbonate: A Comparison


Feature	Calcium Citrate (Citracal)	Calcium Carbonate (Tums)
Elemental Calcium	Lower percentage (approx. 21%)	Higher percentage (approx. 40%)
Stomach Acidity	Does not require stomach acid for absorption; can be taken with or without food	Requires stomach acid for absorption; must be taken with food
Nausea Risk	Generally considered less likely to cause nausea	Higher risk of causing nausea, bloating, and constipation
Dosage	May require more tablets to achieve the same elemental calcium dose	Fewer tablets needed to achieve the same elemental calcium dose
Best For	Individuals with lower stomach acid, those taking acid reflux medication	Individuals with sufficient stomach acid, those who can take it reliably with meals

When to Consult a Doctor

While mild nausea from Citracal can often be managed with simple adjustments, there are situations where you should seek professional medical advice. If you experience persistent or severe nausea, vomiting, confusion, increased thirst or urination, or muscle weakness, contact your healthcare provider immediately. These can be signs of hypercalcemia or other serious issues. Also, if you have recently had bariatric surgery or have a history of kidney stones, it is especially important to consult your doctor before starting or continuing a calcium supplement regimen. For general information, the NIH Fact Sheet on Calcium is a reliable resource.

Conclusion

To answer the question, "Can Citracal cause nausea?" the answer is yes, though this side effect is often mild and manageable. Understanding the reasons behind the discomfort and implementing strategies such as taking the supplement with food, splitting the dosage, or adjusting the timing can effectively alleviate symptoms for most individuals. For those who experience severe side effects or whose symptoms persist, consulting a healthcare provider is the safest course of action to ensure proper calcium intake without unnecessary discomfort. Choosing the right type of calcium supplement for your individual needs is also a crucial step toward a comfortable and effective supplement regimen.

Frequently Asked Questions

Yes, calcium citrate can be taken on an empty stomach, unlike calcium carbonate. However, taking it with food is often recommended to minimize the risk of nausea and other gastrointestinal side effects.

Calcium carbonate is more likely to cause gastrointestinal side effects, including nausea, because it requires stomach acid for absorption. Calcium citrate, being more easily absorbed, is generally gentler on the stomach and causes less nausea.

Yes, the dosage can affect nausea. Taking a large dose all at once is more likely to cause stomach upset. Splitting your daily dose into smaller amounts throughout the day can help prevent nausea.

Yes, severe nausea and vomiting can be a sign of hypercalcemia, or excessive calcium levels. This is a serious condition that requires immediate medical attention. If these symptoms occur, stop taking the supplement and contact a healthcare provider.

Yes, some individuals find that taking their calcium supplement before bedtime helps reduce bothersome daytime nausea. Experimenting with different timing can be an effective strategy for managing side effects.

If taking Citracal with food doesn't resolve the nausea, you could try splitting the dose into smaller amounts throughout the day, switching to a liquid or chewable formulation, or consulting your doctor about alternative calcium sources.

Yes, it is possible. The binding agents used in tablet forms, as well as dyes or other ingredients in the supplement, can sometimes contribute to stomach upset or even allergic reactions.