No, calcium isn't enough: These are the nutrients that actually strengthen your bones.

For years, it's been said that drinking milk is the key to strong bones, but the reality is more complex. Calcium requires other elements to fulfill its function in the body, and one of the most important is vitamin D. This substance allows the body to use calcium from food. If there isn't enough, it can turn to calcium stored in the bones, gradually weakening them .

When phosphorus or calcium levels drop, the body activates a specific form of vitamin D, known as calcitriol . This compound helps release minerals from the bone to compensate for the deficiency. While this mechanism is helpful in the short term, it's not ideal to maintain over time. Furthermore, magnesium is necessary to activate vitamin D properly, so a deficiency prevents the entire process from working properly. The U.S. National Institutes of Health (NIH) explains that without enough magnesium, vitamin D metabolism is compromised. Hence, many supplements combine calcium, magnesium, and vitamin D.

Collagen, elasticity and the need for vitamin C

Collagen plays a structural role in bones: it acts as a foundation for minerals. When it's missing, bones lose some of their elasticity and strength . For the body to produce collagen, it needs vitamin C , found in fruits such as oranges, kiwis, and red peppers. This relationship is officially recognized by the European Union, which emphasizes that vitamin C contributes to normal collagen formation for proper bone function .

Getting these essential nutrients doesn't depend solely on a good diet. Moderate sun exposure —about 10 to 20 minutes daily, according to the NIH —allows the body to generate vitamin D naturally, especially in spring and summer. Added to this is a varied diet that includes oily fish, nuts, green leafy vegetables, and bone broth. If your diet isn't sufficient or deficiencies are detected, supplements can also be used under medical supervision . This helps maintain the balance your bones need to stay healthy . In cases of deficiency, supplements can be considered, but always under medical recommendation, as the Spanish Agency for Food Safety and Nutrition (AESAN) reminds us in its guidelines on bone health.