Can you absorb calcium from drinking hard water?

Dear Reader, 

What makes hard water hard is its high concentrations of calcium, magnesium, and other types of minerals. The minerals from hard water are absorbed by your body the same way they’re absorbed when you consume them in other ways, like drinking a glass of milk or eating an orange. Drinking hard water doesn’t have known adverse health effects and may even help you squeeze some extra minerals into your diet. However, contact with hard water could cause skin dryness, among other side effects. Hard water is often treated with salt-based softeners, which could lead to an overconsumption of sodium. That said, you may choose to use a water softener for several reasons, including limiting skin and hair irritation, preventing build-up in your pipes, and stopping mineral staining. Keep reading to learn about hard water and its effects. 

What is hard water? 

The term ‘hard water’ describes water that naturally has high amounts of calcium and magnesium. As rainwater flows through mountains, rocks, and soil, it absorbs some of the calcium and magnesium that it encounters. These minerals can then make it into your drinking and tap water. 

How is hardness measured and tested? 

Hardness level can be tested through various water testing methods. These tests measure by the total concentration of these two minerals, referred to as the calcium carbonate concentration. The following scale is used to label water hardness: 

• Soft water: under 75 milligrams per liter of calcium carbonate 
• Moderately hard water: 76 to 150 milligrams of calcium carbonate  
• Hard water: 151 to 300 milligrams of calcium carbonate 
• Very hard water: above 300 milligrams of calcium carbonate 

List adapted from Vermont Department of Health  

 Water hardness could also be affected by the presence of metals such as iron, zinc, aluminum, manganese, barium, and strontium, but it is measured based on concentrations of calcium and magnesium. 

Can you absorb minerals from hard water? 

Similar to how your body absorbs calcium and magnesium from foods and drinks, it also absorbs them from the water you drink. Some research suggests that the calcium found in water is just as, if not more, readily absorbable than the calcium found in dairy products like milk.  

Can you consume too much calcium and magnesium by drinking hard water? 

While it’s possible to consume too much calcium and too much magnesium, hard water is usually not the culprit. While there is an upper limit of consumption for these minerals from supplements and fortified foods, there isn’t one for other foods or water. It may also be helpful to keep in mind that an 8-ounce glass of milk contains 300 milligrams of calcium while a glass of moderately hard water only contains 50 to 75 milligrams. 

What are the upper limits of calcium and magnesium from supplements and fortified foods? 

For people ages 19 to 50, the highest amount of calcium that can be consumed without risk is 2,500 milligrams a day. For magnesium, the upper limit is 350 milligrams a day.  

For some, having too much calcium and magnesium in the body can lead to hypercalcemia and hypermagnesemia, respectively. Most often, these conditions are caused by the abnormal production of hormones or other health conditions. However, your body typically has mechanisms in place to protect against the overabsorption of calcium and magnesium. 

What are the health effects of drinking hard water? 

Drinking hard water is not associated with adverse health effects. In fact, it could even help you reach your recommended daily intake of minerals. This benefit is one of the reasons people may drink bottled mineral water.  

Any adverse health effects associated with drinking hard water are typically due to water treatment rather than the hard water itself. Water softeners use different filtering methods, including salt-based and magnetic systems. A salt-based water softener can increase the sodium content of your water. Overconsumption of sodium could lead to long-term health consequences or complicate medical conditions you may already have. If you’re looking to treat your hard water, it’s recommended that you consider the health implications of different types of softeners.  

Although drinking hard water may not lead to adverse health effects, repeated contact with hair and skin could lead to dryness and irritation. If you already have a skin condition that causes dryness, hard water may exacerbate or contribute to your symptoms. If this is a concern, looking into water softeners may be a beneficial next step. 

Are there reasons you might not want hard water in your home? 

While drinking hard water may not have documented adverse health effects, you may wish to treat it with a water softener for other reasons, including: 

• Stain and scum build up on washed clothes, sinks, bathtubs, showers, drains, faucets, heating appliances, and containers used for hot water 
• Reduction of water flow from hot water distribution pipes due to accumulation of minerals  
• Reduction of soap lathering  

List adapted from Vermont Department of Health 

Whether you decide to keep your water hard or employ the use of a softener is up to you! Keeping in mind the different effects of hard water on your health, skin, and home may help you decide what you want to do moving forward.  

Happy drinking!