Strong bones are essential for a healthy and active life. If you have phenylketonuria (PKU), it’s especially important to look after your bone health. Calcium plays a crucial role in keeping bones strong, but meeting calcium needs can be more challenging when following a low-protein diet.
Why is bone health important in PKU?
- Bones are constantly renewing themselves and need key nutrients to stay strong.
- Calcium, phosphate, vitamin D, and vitamin K, which support good bone density.
- About 99% of the calcium in your body is stored in your bones. A lack of calcium can make them weaker over time.
How calcium works in the body
The body regulates the amount of calcium in the blood using hormones such as calcitonin, parathyroid hormone, and vitamin D. If your blood calcium levels drop, your body draws calcium from your bones, which can make them weaker. Ensuring enough calcium intake every day—through food or supplements—is essential for maintaining strong bones.
How to get enough calcium with PKU
Dairy products are a common source of calcium, but they are generally not suitable for people following a low-protein diet. Fortunately, there are other ways to meet your calcium needs.
- Protein substitutes: Most prescribed protein substitutes contain essential micronutrients, including calcium, and are designed to replace the protein you cannot eat from natural sources.
- Not all protein substitutes contain the same amount of calcium. Ask your dietitian about products that provide sufficient calcium for your needs.
- Your calcium requirements change throughout life, so your doctor or dietitian will advise how much you need and how to meet it.
Other sources of calcium in PKU
In addition to protein substitutes, you can increase calcium intake through:
- Low-protein milk substitutes: Some specialist low-protein drinks are fortified with calcium—check labels for nutrient content.
- Plant-based milks such as rice, coconut, or oat drinks—look for fortified varieties, which typically provide around 0.3–1 g of protein per 100 ml and added calcium.
Tips for strong bones in PKU
- Include a daily source of calcium from your diet or supplements.
- Combine calcium with vitamin D to improve absorption.
- Exercise regularly, as physical activity helps strengthen bones.
- Consult your dietitian to choose foods and supplements that best support your needs.
- With the right nutrition, regular monitoring, and smart food choices, you can maintain strong bones and good health—even on a low-protein diet.
