Is RO Water Good for Your Body? An In-Depth Look at Purity and Nutrition

October 8, 2025 •

5 min read

The World Health Organization (WHO) has noted potential health risks associated with long-term consumption of demineralized water. When asking, 'Is RO water good for your body?', it is essential to weigh its superior contaminant-removal capabilities against the fact that it strips away vital minerals during purification.

Quick Summary

Reverse osmosis (RO) systems excel at removing harmful contaminants and impurities, but this process also eliminates essential minerals like calcium and magnesium. To achieve the safest and most nutritionally balanced drinking water, many systems now include remineralization stages.

Key Points

RO Purifies but Demineralizes: The reverse osmosis process removes up to 99% of contaminants like heavy metals and bacteria, but also strips away essential minerals such as calcium and magnesium.
Mineral Loss Can Impact Health: Long-term consumption of demineralized water has been linked by the WHO to potential health issues, including cardiovascular problems and mineral imbalances.
Remineralization is a Recommended Solution: Adding minerals back into RO water through filters or drops is a critical step to ensure it is both pure and nutritionally balanced.
Taste and Acidity are Affected: Demineralized RO water often tastes flat and is slightly acidic due to the lack of minerals. Remineralization improves both the taste and pH.
The Best Option Depends on Your Water Source: An RO system is highly effective for treating water with high TDS or known contaminants, but if your water is already high-quality, the benefits may not outweigh the mineral loss unless remineralized.

The Science Behind Reverse Osmosis

Reverse osmosis (RO) is a water purification technology that uses a semi-permeable membrane to remove a wide range of impurities from water. It is one of the most effective filtration methods available, forcing water through a membrane with pores so small—approximately 0.0001 microns—that only water molecules can pass through. This leaves behind most dissolved solids, including:

Heavy metals like lead, arsenic, and mercury
Pesticides and herbicides
Bacteria, viruses, and other microorganisms
Nitrates, sulfates, and fluoride
Salts and chemicals like chlorine

This high level of purification makes RO water particularly appealing in areas with poor tap water quality, such as sources with high Total Dissolved Solids (TDS) or known contamination. By removing these hazardous elements, RO offers a safer, cleaner, and better-tasting alternative to unfiltered tap water.

The Nutritional Trade-Off: Essential Minerals Removed

While RO's ability to strip water of harmful substances is its main strength, it is also its primary weakness from a nutritional standpoint. The semi-permeable membrane cannot distinguish between harmful and beneficial dissolved minerals, so it removes nearly everything. Key minerals like calcium and magnesium, which are naturally present in water and contribute to our overall daily intake, are lost in the process.

The Health Implications of Demineralized Water

The long-term consumption of demineralized water has been a subject of concern for health organizations. The WHO states that such water has a "definite adverse influence on the animal and human organism". A lack of these minerals in water can lead to several issues, especially if dietary intake is not sufficient to compensate:

Mineral Depletion: Studies on low-mineral water show it can increase the excretion of minerals from the body, contributing to a negative mineral balance.
Cardiovascular Health: Some research has linked the consumption of soft (low-mineral) water with an increased risk of cardiovascular diseases.
Bone Health: The removal of calcium from drinking water can contribute to bone and tooth demineralization over time.
Digestive and Metabolic Issues: Demineralized water can negatively affect the body's homeostatic mechanisms and mineral absorption from food cooked in it, potentially leading to digestive problems.

The pH Factor

Another side effect is that RO water often has a slightly lower pH, making it mildly acidic. This is because the minerals that naturally buffer the water's pH are removed. While this level of acidity is not typically harmful for most healthy individuals, it can contribute to a metallic taste and is a consideration for those with certain health concerns.

Remineralization: A Solution to the Mineral Deficit

Fortunately, advancements in RO technology have largely addressed the issue of mineral loss. Many modern RO systems incorporate a remineralization stage or post-filter, which adds a healthy dose of essential minerals back into the purified water. This step ensures that the water is not only free of contaminants but also nutritionally balanced and great-tasting.

For those with existing RO systems, remineralization can be achieved through several methods:

Remineralization Cartridges: These filters contain mineral media and are installed in-line after the RO membrane to automatically replenish minerals as water is dispensed.
Mineral Drops: Concentrated liquid mineral supplements can be added to a glass or pitcher of RO water. This method offers precise control over mineral content but requires manual application.
Alkaline Pitchers: These pitchers use mineral balls to add beneficial minerals back into the water and can also help raise the pH level.

RO Water vs. Tap Water: A Comparison

To fully understand the trade-offs, here is a comparison of typical municipal tap water with un-remineralized RO water and remineralized RO water.


Feature	Municipal Tap Water	Un-Remineralized RO Water	Remineralized RO Water
Contaminants	Variable, depends on source and treatment. Can contain chlorine, heavy metals, etc.	Very low; up to 99% of contaminants removed.	Very low; same high-level contaminant removal as standard RO.
Mineral Content	Variable; often contains beneficial minerals like calcium and magnesium.	Very low, stripped of almost all minerals.	Balanced mineral content, with essential minerals added back.
Taste	Variable; can have off-tastes due to chlorine or mineral levels.	Often described as flat or bland due to lack of minerals.	Improved, crisp taste due to balanced mineral content.
pH Level	Typically neutral or slightly alkaline.	Mildly acidic due to lack of buffering minerals.	Neutral or slightly alkaline, balanced by added minerals.
Environmental Impact	Minimal water waste from the purification process.	Significant water wastage during the purification process.	Significant water wastage from the purification process.

Conclusion: A Balanced Approach to Hydration

Is RO water good for your body? The answer depends on your water source and whether the water is remineralized. For households with high-TDS water or concerns about specific contaminants, an RO system is an excellent choice for safety. However, the mineral-stripping process is a nutritional drawback that requires a proactive solution.

For most people, the safest and most nutritionally sound approach is to choose an RO system that includes a remineralization filter. This provides the best of both worlds: highly purified water that is free of harmful substances and enriched with the essential minerals your body needs for optimal health. Long-term consumption of properly remineralized RO water is generally considered safe, providing peace of mind and clean, healthy hydration.

For more information on water quality and safety, the World Health Organization is a leading authority on setting standards and guidelines: https://www.who.int/news-room/fact-sheets/detail/drinking-water.

How to Assess Your Water Needs

To determine if a standard or remineralized RO system is the right choice for your household, consider the following:

Test Your Tap Water: A TDS meter can give you a quick reading on your water's dissolved solids. High readings may indicate a need for advanced filtration like RO.
Evaluate Your Diet: If your diet is rich in minerals from fruits, vegetables, and dairy, the mineral loss from un-remineralized RO water may be less of a concern. However, for many, dietary sources alone do not fully compensate.
Consider Vulnerable Groups: For infants, pregnant women, and the elderly, ensuring adequate mineral intake is even more critical. Remineralized RO water or consulting a healthcare professional is advisable.

By taking a balanced approach, you can enjoy the benefits of highly purified water without compromising on essential nutrition.

Frequently Asked Questions

RO water is highly effective at removing harmful contaminants, making it safe from waterborne pathogens and many chemicals. However, for optimal nutrition, it is recommended to drink remineralized RO water, as the purification process removes beneficial minerals like calcium and magnesium.

Prolonged consumption of exclusively demineralized RO water can lead to mineral deficiencies if your diet does not sufficiently compensate for the lack of minerals. This is why many RO systems now feature a remineralization stage.

Yes, remineralizing RO water is highly recommended. It not only restores essential minerals vital for bodily functions but also improves the taste and balances the slightly acidic pH of the purified water.

RO water is mildly acidic because the mineral buffers are removed. While this is not generally harmful to healthy individuals, remineralization can restore a neutral or slightly alkaline pH and is considered a healthier long-term option.

The most convenient method is to use an RO system with a built-in remineralization cartridge. Alternatively, you can use mineral drops, an alkaline pitcher, or add a pinch of mineral salt like Himalayan salt manually.

For most people with a varied diet, the primary source of minerals comes from food. However, minerals from water are more bioavailable, and studies suggest that dietary intake may not fully compensate for the complete removal of minerals from drinking water.

Yes. Un-remineralized RO water often tastes flat or bland due to the absence of dissolved minerals. When minerals are added back during remineralization, the water’s taste is significantly improved.