Drinking water that has been demineralized, also known as deionized water, can potentially lead to negative health effects for some people. Demineralized water has had all of its minerals, such as calcium, magnesium, and potassium, removed through a process called ion exchange. While safe for occasional consumption, relying solely on demineralized water for hydration may cause mineral deficiencies over time.
How Demineralized Water is Produced
Demineralized water goes through a multi-step process to remove dissolved minerals and ions. First, the water passes through a cation resin filter which attracts and binds to positively charged mineral ions like calcium and magnesium. Next, it flows through an anion resin filter that attracts negatively charged ions like chloride and sulfate. This process removes nearly all dissolved mineral salts and ions, leaving behind water that is essentially pure H2O.
The resulting demineralized water has a very low electrolyte and mineral content, with a total dissolved solids (TDS) level of 0-10 parts per million. In comparison, tap water generally contains 150-350 ppm TDS. Even spring water, considered very low in dissolved solids, usually contains at least 50 ppm.
The Importance of Minerals in Water
While pure water may sound ideal, minerals play many important roles in the body. Electrolytes like calcium, magnesium, and potassium help regulate muscle function, nerve signaling, hydration, blood pH, and more. Trace elements like lithium, boron, and strontium also have biological functions.
Drinking water is a major way we obtain essential minerals and electrolytes. In areas with hard water, tap water can provide up to 20% of the recommended daily calcium intake. When mineral intake is insufficient, demineralized water can potentially leach minerals from the body as it is excreted.
Potential Negative Effects of Drinking Demineralized Water
Drinking demineralized water long-term could lead to negative health effects for some people:
1. Electrolyte Imbalances
Because demineralized water is lacking in electrolytes, relying on it as your sole source of hydration can lead to electrolyte deficiencies and imbalances over time. This may result in:
Fatigue, lethargy, and weakness
Muscle cramps and spasms
Bone loss and increased fracture risk
Those who sweat heavily, such as athletes and outdoor workers, have increased electrolyte needs and may experience electrolyte imbalance symptoms more readily when drinking demineralized water.
2. Mineral Deficiencies
Demineralized water provides none of the calcium, magnesium, selenium, or other trace minerals that drinking water normally contains. This can contribute to mineral deficiencies. Potential effects include:
Calcium deficiency - Increased risk of osteoporosis
Magnesium deficiency - High blood pressure, muscle cramps, anxiety
Zinc deficiency - Weakened immune system, diarrhea
Chromium deficiency - High blood sugar, glucose intolerance
Those already deficient or at-risk for deficiency in certain minerals are most vulnerable to the effects of demineralized water.
3. Gastrointestinal Distress
The lack of minerals makes demineralized water highly hypotonic, meaning it has very low osmolality compared to bodily fluids and cells. Some people report mild diarrhea or digestive discomfort after drinking demineralized water, especially in large amounts.
This is because water passes through the digestive tract faster when mineral content and osmolality are low. The food also remains more poorly digested. Minerals like calcium and magnesium normally aid digestion.
4. Altered Taste
Many people dislike the flat, mineral-free taste of demineralized water, describing it as unnatural or unrefreshing. Expectations about how water should taste based on one's local water supply may also make people perceive the taste of demineralized water negatively.
5. Leaching Minerals from Pipes
When passed through metal pipes and plumbing systems, demineralized water tends to leach out minerals like copper, lead, and zinc more aggressively. This can contaminate the water with potentially harmful metals.
Highly demineralized water also corrodes and degrades pipes faster than regular drinking water. Choosing electrolyte-enhanced bottled waters may prevent plumbing-related issues.
Health Risks for Specific Groups
While most people can safely drink demineralized water occasionally with little concern, some groups are more vulnerable to adverse effects with regular long-term use:
Infants and Young Children - Infants have electrolyte needs up to double that of adults. Relying on demineralized water during critical growth periods could lead to developmental issues.
Pregnant Women - Pregnant women have increased calcium, magnesium, and electrolyte needs. Drinking demineralized water may increase risk of deficiencies.
Elderly Adults - Many elderly struggle with maintaining mineral and electrolyte balance. Demineralized water could exacerbate imbalances and deficiencies.
Athletes and Outdoor Workers - Sweat results in substantial electrolyte losses. Demineralized water cannot replenish electrolytes lost while sweating heavily during exercise.
Those with Kidney Disease or on Dialysis - Individuals with kidney disease or on dialysis are prone to electrolyte imbalances and often must closely monitor mineral intake.
Those with Chronic Deficiencies or GI Disorders - Those deficient in minerals or with digestive disorders like IBS may experience more severe symptoms from demineralized water.
If you fall into any of these high-risk groups, discuss with your doctor before making demineralized water your primary drinking water source.
Safe Use of Demineralized Water
While potentially risky as your sole source of hydration, demineralized water can be safely consumed in moderation as part of a mineral-rich diet:
Use demineralized water occasionally, but rely primarily on mineralized water sources.
Take care to obtain adequate calcium, magnesium, and electrolytes from foods. Dairy, nuts, legumes, meat, seafood, dark leafy greens, avocados, and bananas tend to be good sources.
Add electrolyte tablets or mineral drops to demineralized water for improved taste and reduced health risks.
Monitor for any symptoms of electrolyte imbalance like muscle cramps, fatigue, or heart palpitations. Stop drinking demineralized water if these occur.
Those in high-risk groups should limit demineralized water intake and consult a doctor if concerned.
Use bottled water and pitcher filters labeled as "mineral-balanced" or "electrolyte-enhanced" for safer mineralized water.
Overall, demineralized water is safe to drink but lacks the important nutritional benefits that minerals and electrolytes provide. While it makes up for poor taste or odor, relying solely on demineralized water long-term may lead to deficiency issues for some individuals.
H2 Recommending Mineralized Water Options
To enjoy purified water while still obtaining essential minerals, consider these safer mineralized water options:
Mineralizing Filter Systems
Certain water filters like the AquaRevive Reverse Osmosis System use a remineralization stage. This adds back beneficial minerals like magnesium, calcium, and potassium after the standard filtration process.
Reverse osmosis systems with remineralization allow you to enjoy purified water with reduced contaminants, while also receiving healthy minerals. Look for systems with multiple remineralization stages for optimal mineral content.
Mineralizing Water Drops & Tablets
Adding mineral drops or electrolyte tablets to demineralized or purified water can greatly improve its nutritional value. Products like Ultima Replenisher, Hi-Lyte, and NormaLyte contain bioavailable forms of electrolytes and minerals your body needs.
This offers the purification of demineralized water alongside the nutrition of mineral water. Adding even small amounts of these mineralizing supplements to your water can make a big difference.
Natural mineral water sourced from springs has an ideal balance of purity and natural mineral content. Brands like Gerolsteiner, San Pellegrino, Perrier, and Evian provide both minerals and the crisp, clean taste of spring water.
With around 50-400 ppm TDS, mineral water offers both high purity and needed electrolytes. Just check labels and avoid any very high sodium options.
Enhanced Bottled Waters
Look for purified or spring bottled waters labeled "mineral-enhanced," "mineral-balanced," or "electrolyte-enhanced." These contain added beneficial minerals like calcium and magnesium to make demineralized water healthier and tastier.
SmartWater, AquaHydrate, Evermore, and Hint are just a few brands that now sell electrolyte-enhanced purified waters. This makes them safer for regular drinking than standard demineralized water.
The Bottom Line
While drinking the occasional glass of demineralized or deionized water is harmless for most people, relying on it as your only water source can potentially lead to negative effects in some individuals due to mineral imbalance.
Seeking out mineral-balanced waters, enhanced bottled waters, mineralizing filters, or mineral drops is recommended for more regular consumption. If you have kidney issues, are pregnant, or fall into another high-risk group, exercise particular caution and consult your doctor before making demineralized water your go-to hydration source.