What will happen if I drink too much calcium?: Understanding the Dangers of Hypercalcemia

October 25, 2025 •

3 min read

Although calcium is vital for strong bones, nerves, and muscles, excessive intake, particularly from supplements, can lead to a dangerous condition known as hypercalcemia. This can have significant repercussions for your health, including kidney stone formation and cardiovascular issues. So, what will happen if I drink too much calcium? It is crucial to understand the causes, symptoms, and long-term effects of this imbalance to maintain your well-being.

Quick Summary

Excessive calcium intake can lead to hypercalcemia, causing symptoms from kidney stones and digestive issues to serious cardiac and neurological problems, especially when consumed via supplements.

Key Points

Hypercalcemia: Excessive calcium in the blood, often caused by supplements, certain diseases, or high vitamin D intake.
Diverse Symptoms: Early signs include excessive thirst, frequent urination, constipation, and fatigue. More severe symptoms involve bone pain, confusion, and heart palpitations.
Kidney and Heart Risks: Long-term excessive calcium can lead to painful kidney stones, irreversible kidney damage, and may increase the risk of heart arrhythmias and vascular calcification.
Supplements vs. Food: The risk of hypercalcemia is significantly higher from over-supplementation than from dietary intake. Your body regulates absorption from food more effectively.
Seek Medical Advice: Always consult a healthcare provider before taking calcium supplements to determine the appropriate dosage and avoid potential health complications, especially if you have existing conditions or take other medications.
Know Your Limit: The Tolerable Upper Intake Level (UL) for calcium is 2,500 mg per day for adults 19–50 and 2,000 mg for those over 50. Exceeding this can increase health risks.

What is Hypercalcemia?

Hypercalcemia is a condition where calcium levels in the blood are too high. Calcium is essential for many bodily functions, including nerve and muscle activity and blood clotting, with most of it stored in the bones. The body usually keeps blood calcium levels balanced with hormones like parathyroid hormone and vitamin D. However, disruptions to this balance can cause various health problems.

Causes of Excessive Calcium Intake

While medical conditions are the most frequent cause of hypercalcemia, taking too much calcium or vitamin D through supplements is a significant risk factor.

Excessive Supplementation: High doses of calcium supplements can elevate blood calcium, a risk less common with dietary calcium because the body regulates food-based absorption more effectively.
Excessive Vitamin D Intake: Since vitamin D helps absorb calcium, too much of it can lead to increased calcium absorption and potentially hypercalcemia.
Overactive Parathyroid Glands: The most common cause is hyperparathyroidism, where the parathyroid glands produce excess hormone, increasing calcium release from bones.
Cancer: Certain cancers can lead to hypercalcemia by producing PTH-like proteins or causing bone breakdown.
Other Medical Conditions: Sarcoidosis, tuberculosis, and prolonged immobility can also contribute to high calcium levels.
Milk-Alkali Syndrome: This can result from consuming large amounts of calcium carbonate, often found in antacids, along with absorbable alkali.

The Symptoms of Too Much Calcium

Symptoms of hypercalcemia vary from mild to severe, depending on the calcium level and rate of increase. They can affect multiple body systems:

Kidney-related symptoms:

Increased thirst and frequent urination
Kidney stone formation
Potential kidney function decline

Digestive symptoms:

Stomach pain, nausea, and vomiting
Loss of appetite
Constipation

Muscular and Skeletal symptoms:

Muscle weakness and aches
Bone pain and increased fracture risk

Neurological symptoms:

Fatigue and lethargy
Confusion and difficulty concentrating
Depression or irritability
Severe cases may lead to stupor or coma

Cardiac symptoms:

Heart palpitations and irregular rhythms
Changes in heart's electrical activity

Long-Term Health Consequences

Persistent hypercalcemia can cause lasting damage, particularly to the kidneys and cardiovascular system.

Kidney Damage: High calcium can lead to nephrocalcinosis and chronic kidney disease.
Cardiovascular Disease: Some studies suggest a link between high supplemental calcium and increased risk of heart problems due to calcium buildup in arteries.
Bone Weakening: Paradoxically, conditions causing hypercalcemia can weaken bones by drawing calcium from them, increasing fracture risk.
Soft Tissue Calcification: In severe cases, calcium deposits can form in soft tissues.

Dietary vs. Supplemental Calcium: A Comparison

It is difficult to get too much calcium from food due to the body's natural absorption control. The risk of hypercalcemia is mainly linked to supplements.


Feature	Calcium from Diet	Calcium from Supplements
Hypercalcemia Risk	Very low due to natural regulation.	Higher, especially exceeding recommended upper limits.
Absorption	Absorbed more gradually and effectively.	Large doses can overwhelm regulatory systems.
Heart Health Concerns	Linked with lower heart disease risk.	Some studies suggest increased cardiovascular risk with high intake.
Side Effects	Not typically associated with side effects.	Can cause digestive issues like constipation and bloating.
Sources	Dairy, leafy greens, fortified foods.	Tablets, capsules, powders, antacids.

How to Safely Manage Calcium Intake

Prioritize Food Sources: Aim to meet calcium needs through foods like dairy, fortified plant milks, and leafy greens.
Know Your Needs: Calcium requirements vary; adults aged 19-50 need 1,000 mg, and women over 50 need 1,200 mg. Consult a healthcare provider for personalized advice.
Use Supplements Wisely: If supplements are needed, do not exceed the upper limits (2,500 mg for adults 19-50, 2,000 mg for those over 50). Splitting doses can help absorption.
Ensure Sufficient Vitamin D: Adequate vitamin D is vital for calcium absorption, but avoid excessive intake.
Stay Hydrated: Drinking enough water helps the kidneys process excess calcium.
Consult a Professional: Always talk to a doctor or dietitian before starting supplements, especially with existing health conditions or medications.

Conclusion

While calcium is crucial for health, excessive amounts, particularly from supplements, can cause hypercalcemia with serious consequences like kidney and heart damage. Obtaining calcium from food is generally safer as the body regulates its absorption well. By understanding the risks and following recommended guidelines, you can benefit from calcium without risking your health. Always seek professional advice regarding supplementation.

Frequently Asked Questions

Initial signs of hypercalcemia are often subtle and include excessive thirst, frequent urination, fatigue, muscle weakness, and constipation. Headaches and stomach pain can also occur as the condition progresses.

It is very unlikely to get too much calcium from food alone because the body regulates its absorption from dietary sources effectively. Excess calcium intake is typically from supplements or an underlying medical condition.

Recommended daily calcium intake varies: adults aged 19–50 need 1,000 mg, while women over 50 and men over 70 need 1,200 mg. The Tolerable Upper Intake Level is 2,500 mg for adults 19-50 and 2,000 mg for those over 50.

Milk-alkali syndrome results from consuming excessive calcium, often from antacids, along with absorbable alkali. It can lead to hypercalcemia, metabolic alkalosis, and kidney problems.

Treatment depends on severity and cause. Mild cases might only need increased fluid intake. More severe cases may require medications, IV fluids, and treatment of the underlying cause, potentially including surgery.

Some studies suggest a link between high supplemental calcium and increased cardiovascular risk. This might be due to calcium deposits in arteries, but more research is needed.

Severe hypercalcemia can cause neurological symptoms like confusion, memory issues, fatigue, and depression. In very severe cases, it can lead to stupor and coma.