What Does Demineralized Water Do to the Body? A Comprehensive Health Analysis

December 25, 2025 •

3 min read

The World Health Organization (WHO) has stated that consuming water with low mineral content can have a negative impact on the body's mineral and water metabolism. While many purification methods can produce demineralized water, it is not considered suitable for regular consumption and presents several health concerns. Understanding what demineralized water does to the body is crucial for making informed hydration choices.

Quick Summary

Long-term consumption of demineralized water can lead to mineral deficiencies and disrupt the body's electrolyte balance. This occurs because the purification process strips out essential minerals like calcium and magnesium. Potential adverse health effects include increased risk of cardiovascular and dental problems, along with the leaching of minerals from the body's tissues.

Key Points

Electrolyte Imbalance: Demineralized water can disrupt the body's electrolyte balance, potentially leading to symptoms like fatigue, headaches, and muscle cramps.
Mineral Leaching: Due to osmosis, mineral-free water can cause the body to excrete more essential minerals, which are drawn from the body's reserves to maintain balance.
Cardiovascular Risks: Chronic consumption of low-mineral water is associated with an increased risk of cardiovascular diseases due to a lack of minerals like magnesium and calcium.
Detrimental to Bones and Teeth: The absence of beneficial minerals can lead to the demineralization of bones and teeth, increasing risks of osteoporosis and dental caries.
Requires Remineralization: For safe, regular consumption, demineralized water produced by methods like reverse osmosis must be remineralized to add back essential minerals.

Understanding Demineralized Water

Demineralized water is water from which dissolved mineral ions have been removed through processes like ion exchange, reverse osmosis, or distillation. This makes it suitable for industrial, laboratory, and medical uses where mineral-free water is required. However, its lack of minerals makes it problematic for human consumption. While similar, demineralized water via ion exchange differs from distilled water as it may not be free of organic contaminants or microorganisms.

The Physiological Consequences of Consuming Mineral-Free Water

Drinking demineralized water impacts the body's ability to maintain stable internal conditions (homeostasis). The body is used to processing water with minerals, so consuming water without them triggers negative responses:

Electrolyte Imbalance: The absence of minerals can dilute the body's electrolytes, like sodium, potassium, calcium, and magnesium. The body may draw these from tissues to compensate, potentially causing fatigue, headaches, muscle cramps, and heart issues. Drinking large amounts of low-mineral water, especially after exercise, can lead to severe low sodium levels (hyponatremia).
Increased Mineral Loss from the Body: Instead of adding minerals, demineralized water can increase mineral excretion through urine. Studies showed that consuming low-mineral water increased urine output and the loss of essential ions as the body tries to rebalance fluids and electrolytes.
Nutrient Leaching During Cooking: Using demineralized water for cooking can remove nutrients from food. Vegetables cooked in it can lose a significant amount of their mineral content through osmosis.

Long-Term Health Risks

Extended consumption of demineralized water is linked to several health concerns due to the ongoing challenge to the body's stability.

Cardiovascular Disease: Studies suggest a link between drinking soft water (low in calcium and magnesium) and increased cardiovascular problems, as these minerals are vital for heart health.
Bone Health Issues: Low levels of calcium and other minerals in drinking water can negatively affect bone density. Some research suggests low-calcium water is linked to a higher risk of childhood fractures and can contribute to osteoporosis.
Dental Health Degradation: Demineralized water lacks minerals like calcium and fluoride that strengthen enamel, increasing the risk of cavities. Its aggressive nature can even draw minerals from teeth.
Increased Risk from Toxic Metals: Paradoxically, demineralized water can leach toxic metals like lead and cadmium from pipes because it is unstable. Minerals in regular water offer some protection against absorbing these metals.

The Need for Remineralization

Due to the health risks, remineralizing water is crucial for consumption. This adds back essential minerals to support health. The WHO recommends minimum levels for Total Dissolved Solids (TDS), calcium, and magnesium in drinking water.

Common Minerals Added During Remineralization

Calcium: Important for bones, teeth, and muscle function.
Magnesium: Essential for many bodily functions, heart health, and muscles.
Potassium: Key electrolyte for nerve function and fluid balance.
Sodium: Another vital electrolyte for maintaining fluid balance.

Comparison: Demineralized vs. Tap Water


Feature	Demineralized Water	Regular Tap Water
Mineral Content	Almost completely free of dissolved minerals (TDS < 10 mg/L).	Varies by source, contains essential minerals like calcium, magnesium, and sodium.
Purification Process	Ion exchange, reverse osmosis, or distillation.	Municipal treatment plants using filtration, chlorination, and other methods.
Taste	Often described as flat, unappealing, or "off" due to lack of minerals.	Flavor profile is affected by its mineral composition. Hard water may taste chalky.
Health Effects (Drinking)	Can cause mineral deficiency, electrolyte imbalance, and other long-term health risks if not remineralized.	Generally safe to drink (in developed countries) and provides some dietary minerals.
Industrial Use	Widely used in laboratories, manufacturing, and automotive industries due to its purity.	Not suitable for applications requiring high purity due to mineral content.

Conclusion: Demineralized Water is Not for Drinking

Demineralized water is essential for industry and science but unsuitable for drinking without remineralization. The purification removes essential minerals and electrolytes needed for bodily functions. Long-term consumption can disrupt mineral balance, leading to health issues like electrolyte imbalances, bone problems, and cardiovascular risks. For healthy hydration, drink water with adequate minerals. If using systems like reverse osmosis, remineralization is necessary for safe, supportive drinking water.

For more information on water quality and safety standards, refer to the World Health Organization's Guidelines for drinking-water quality.

Frequently Asked Questions

While both lack significant mineral content, they are produced differently. Distillation involves boiling and condensing, which removes both minerals and organic contaminants. Demineralization, typically using ion exchange, removes mineral ions but may not eliminate viruses or bacteria.

The flat or unappealing taste is due to the lack of dissolved minerals and salts. These minerals are what give water its characteristic flavor. With them stripped away, the taste is noticeably different and often less thirst-quenching.

Using demineralized water for cooking is not recommended. When cooking foods like vegetables in mineral-free water, the process can cause the foods to lose a significant portion of their own essential minerals through osmosis.

Consuming small amounts of demineralized water as part of a balanced diet is generally not considered dangerous. The risks arise with prolonged, exclusive consumption, especially without a diet rich enough to compensate for the mineral deficit.

To make it safe for drinking, you must remineralize it. This can be done by using remineralization cartridges, or by adding mineral drops or a pinch of mineral-rich salt. This restores essential minerals like calcium and magnesium.

Early symptoms of mineral or electrolyte imbalance from consuming demineralized water can include tiredness, weakness, headaches, and muscle cramps. More severe symptoms involve impaired heart rate and potential delirium.

While a balanced diet is the primary source of minerals, it may not be sufficient to fully compensate for the lack of minerals in drinking water, especially if the diet itself is borderline deficient. The minerals in water are often more readily absorbed.