How Purification Removes Minerals
When sourcing bottled water with a low or nonexistent calcium content, it is essential to understand the methods manufacturers use. The key to creating water with a minimal mineral profile is processing it to strip away naturally occurring elements, rather than sourcing it from a location that is naturally low in minerals.
Distilled Water: Complete Mineral Removal
Distilled water is created by boiling water and collecting the resulting steam. As the steam condenses back into liquid, it leaves behind any minerals and impurities. This process results in extremely pure water with virtually no dissolved solids, including calcium.
Advantages of Distilled Water:
- Extremely high purity with zero minerals.
- Free from contaminants, bacteria, and chemicals.
Disadvantages of Distilled Water:
- The taste is often described as 'flat' or 'boring' due to the complete lack of minerals.
- The distillation process is energy-intensive and can be less environmentally friendly than other methods.
Reverse Osmosis Water: High-Level Filtration
Reverse osmosis (RO) is a purification process where water is forced through a semipermeable membrane. This membrane filters out most dissolved solids, including a significant amount of the water's mineral content. RO systems typically remove around 98% of the total dissolved solids, leaving a very low mineral concentration. Many commercial purified water brands, like Aquafina, use this technology.
Advantages of Reverse Osmosis Water:
- Highly effective at removing contaminants and most minerals.
- Provides a consistently clean and fresh taste.
Disadvantages of Reverse Osmosis Water:
- May not be 100% free of calcium, as some may slip through the membrane.
- The process can be wasteful, as it uses more water than it produces in purified form.
Popular Bottled Water Brands with Low or No Calcium
For consumers seeking water with minimal calcium, focusing on brands that label their products as "purified" or "distilled" is the best approach. Here are some examples:
- Aquafina: Owned by Pepsi, Aquafina is municipal water purified using a multi-step process that includes reverse osmosis. It has a very low TDS (Total Dissolved Solids) content, indicating minimal minerals, including calcium.
- Nestlé Pure Life: This is another major brand that uses a purification process, often including reverse osmosis. The company explicitly states that its purified water does not contain added minerals.
- Smartwater: This brand is made from municipal sources and is distilled, which removes virtually all minerals. After distillation, electrolytes are added back for taste, but the calcium content remains extremely low.
- Dasani: While it is purified using reverse osmosis, Dasani does add back a blend of minerals, including potassium chloride. This means its mineral content is slightly higher than Aquafina, but still far lower than a natural mineral water.
Comparison of Water Types
| Water Type | Main Processing Method | Typical Calcium Content | Taste Profile |
|---|---|---|---|
| Mineral Water | Naturally sourced, no added minerals | High (often > 200 mg/L) | Distinct, dependent on mineral composition |
| Spring Water | Sourced from a natural spring | Variable (often low-to-moderate) | Generally clean, can have unique terroir |
| Purified Water (RO) | Reverse Osmosis | Negligible (but not zero) | Clean, neutral taste |
| Distilled Water | Boiling and re-condensing | Zero | Flat, tasteless |
Health Considerations for Low-Calcium Water
Some individuals choose low-calcium water for specific health reasons, such as concerns about kidney stones. While calcium from diet is generally beneficial, some studies suggest that high-mineral water intake could be a factor in some cases. However, the human body primarily gets its necessary minerals from food, not water. If you consistently drink water with no minerals, it's crucial to maintain a balanced diet rich in calcium and other nutrients. Drinking demineralized water is generally considered safe but offers no mineral health benefits.
How to Check for Calcium Content
To be certain about the mineral content of your bottled water, you should look for specific indicators on the label:
- Total Dissolved Solids (TDS): This value is usually listed on the nutrition facts or label. A very low TDS (less than 10 ppm) indicates a minimal mineral presence. Distilled water will have a TDS of 0.
- Ingredients List: Check if minerals are listed as "added electrolytes" or "for taste." Some brands add them back after purification. For a truly calcium-free option, you want a product with no added minerals.
- Product Description: Look for words like "purified," "distilled," or "demineralized." These terms indicate a process that has removed the minerals. Avoid "mineral water" and check "spring water" carefully.
Conclusion
When seeking bottled water that does not have calcium in it, the most reliable choices are products labeled as "purified" through methods like reverse osmosis or, for a completely mineral-free option, "distilled." Brands such as Aquafina and Nestlé Pure Life are popular purified choices with minimal mineral content. While perfectly safe for most, individuals relying solely on demineralized water should ensure they receive adequate calcium through their diet. Always check the label for a low TDS reading or specific purification methods to confirm the calcium content. For further information on mineral content in water, refer to the National Institutes of Health.
