Why Calcium Alone Isn’t Enough for Strong Bones

The familiar public health message tells us to focus on calcium for strong bones.  While this is true, it is an oversimplistic view of bone health.   

 

In reality, many other nutrients are just as important.  These bone-supporting vitamins and minerals work together as a team — along with calcium — to keep your bones strong and healthy from childhood through the older years.  

 

How does calcium support bone health? 

 

To understand how other nutrients contribute to the health of your bones, it’s helpful to start at the beginning with calcium.  Calcium is the most abundant mineral found in your body.  It is so tightly regulated that the body will break down bones if intake through diet or supplements is lacking.   

 

Aside from being a major building block of bone, calcium also plays a role in cellular signaling.i  You can find a small amount of calcium in your blood and cells, but close to 99 percent is found in your bones and teeth.ii 

 

As you age, bone breakdown increases while bone formation slows down, especially in postmenopausal women.  These changes result in bone mass loss and integrity issues.  The association between calcium and bone health became a public health message after several studies found a positive connection between calcium intake in the diet and bone health.  But what about the other nutrients they ate? 

 

In reality, the relationship is not so black and white.  An extensive review examining many different studies focused on the relationship between calcium intake bone health in the elderly found mixed results between calcium intake and risk of fracture.  The authors found that calcium did not appear to be associated with a reduced risk of fracture. Thus, they concluded that the evidence supporting calcium supplements alone for bone health is weak at best.iii 

 

So, should you skip calcium for healthy bones? 

 

The answer is no. Calcium does matter for your bones, but it doesn’t work by itself.   

 

There are noticeable benefits when calcium is combined with other nutrients.  For example, a meta-analysis of studies that used calcium in combination with vitamin D illustrated the benefit of supplementation with both nutrients for reducing fracture risk, especially hip fractures.iv 

 

These results suggest that while calcium is essential, one single nutrient isn’t enough.  This conclusion makes sense because in the real world nutrients don’t exist in a vacuum.  When you eat a meal, you take in vitamins and minerals that work synergistically together.  So theoretically, your supplements should work similarly, as our body uses the combination of all of these nutrients to support our bone health.v  

 

 

What other nutrients support strong bones? 

 

Vitamin D3 

 

As mentioned above, vitamin D has been well-studied for its positive impact on bone health, combined with calcium for supporting strength and fracture risk reduction.vi  An essential fat-soluble vitamin, the primary source of vitamin D is through sun exposure since it’s challenging to get enough through the diet.  However, because of skin pigmentation, sun protection, and climate differences, many people have suboptimal levels.   

 

Osteoblasts, the cells that form bone, have vitamin D receptors on their surfaces.vii  As a result, vitamin D may help support the formation of new bone cells and bone tissue.viii  Vitamin D may also influence the expression of genes for bone protein and growth factors.ix  Higher doses of vitamin D supplementation during pregnancy could even lead to stronger bones for children as they grow.x 

 

Magnesium 

 

Another less talked about mineral for bone support is magnesium.  Magnesium works synergistically with other bone-building nutrients in the body.  It’s especially beneficial for supporting bone mineral density, an important measurement for bone health.  Magnesium may help with bone health because it impacts vitamin D activity and supports a healthy vitamin D status alongside calcium.xi 

 

Studies show that lower levels of magnesium are associated with bone health concerns.xii  Further, people who take in lower amounts of magnesium in their diet appear to have an increased risk of fracture and reduced bone mineral density. At the same time, supplementation supports bone mineral density and reductions in bone breakdown. xiii xiv 

 

Zinc  

 

Zinc is another trace mineral that contributes to your bone health.xv  About thirty percent of the zinc in your body is found in bone.xvi  Zinc is primarily found in high protein foods, especially shellfish. 

 

In combination with calcium, vitamin D, and magnesium, zinc helps with bone mineralization.xvii  Zinc supports the formation and regeneration of new bone by stimulating osteoblasts.  It also helps to inhibit bone breakdown and is needed for optimal calcium absorption.xviii  Conversely, suboptimal zinc levels are associated with reduced skeletal growth, bone density, and even lower levels of collagen synthesis.xix 

 

Copper  

 

Copper works in tandem with zinc — and the ratio of the two is essential for bone health and beyond.  Once again, you may not immediately consider copper a bone-building nutrient, but it plays a role in building the enzymes needed for collagen to support the structure of bone. 

 

Similar to zinc, copper also works by limiting the breakdown of bone.xx  Without enough copper, the risk of bone health conditions is increased, and bones can grow abnormally because of the reduced enzyme production mentioned above.xxi 

 

Vitamin C 

 

While you may primarily think of vitamin C for its immune benefits, it also plays a role in your bone formation.  Vitamin C (or ascorbic acid) intake through diet and supplementation is associated with supporting bone mineral density, especially in menopausal women.  Its positive effects may be related to vitamin C’s ability to impact gene expression for bone matrix in osteoblasts.xxii 

 

Manganese 

 

Manganese is a trace metal that once again works synergistically with other bone supporting nutrients to support improvements in bone density.  The studies on manganese for bone health are not as robust as compared to many other nutrients. Still, they do point towards its collaborative role.  Manganese acts as a co-factor for building bone cartilage, collagen, and bone mineralization.xxiii 

 

Lower levels of manganese intake are associated with reduced bone density.  And studies that used supplemental manganese combined with calcium, copper, and zinc saw improvements in bone maintenance after menopause, compared to a placebo group.xxiv 

 

 

Vary your nutrients for bone health 

 

As you can see, many different nutrients impact bone health.  Supporting bones requires a balance of all of these nutrients.  A diet rich in fresh produce, whole grains, and healthy protein will help to provide sources of these vitamins and minerals into your daily intake. However, supplementation can be especially beneficial to make sure you are meeting all your bone-nutrient needs.