Calcium, Dairy and Strong Bones– What’s the Evidence?
A recent survey by The Dairy Alliance found 89% of parents believe children today do not get enough calcium yet admit they do not know how much calcium they need. Turns out, parents are right! In fact, adolescents seem most at risk for not getting enough calcium which is when needs are at their highest. The Dietary Reference Intakes for calcium, revised in 2011, state most children between the ages of 1 to 18 need between 700 and 1,300 mg of calcium daily. In honor of May’s National Osteoporosis Awareness Month and National Nutrition Research Month, let’s take a look at a few of the many studies that support consumption of dairy to build strong bones.
Dairy products are a rich natural source of calcium, and three dairy servings daily can provide sufficient amounts of calcium for most children. However, when choosing dietary sources, bioavailability should be considered. This refers to the amount of food calcium that is absorbed and utilized by the body including incorporated into bone. Although you can obtain dietary calcium through vegetarian sources such as leafy greens and legumes as well as fortified products, bioavailability of most of these alternatives may be less than from dairy sources.
In addition, dairy contains other bone-building nutrients such as protein and vitamin D which improve lean mass which is important in maintaining the integrity of bone. In fact, it may be the synergistic effects of these nutrients in dairy which help improve bone mineral density. A systematic review by the National Osteoporosis Foundation cited three randomized clinical trials which all found improvements in adolescent bone with dairy consumption. Interestingly, probiotics (the good bacteria found in cultured dairy foods like yogurt and influence the gut microbiota) are being increasingly recognized as also playing a role in bone metabolism.
So, what’s the take home message? The evidence suggests dairy products contain a good balance of nutrients which aid in bone growth and health. A healthy diet, which includes dairy, combined with daily physical activity can help in building strong bones.
Sina Gallo, PhD, is a Registered Dietitian and Assistant Professor in Nutrition and Food Studies at George Mason University. Dr. Gallo’s research focuses on improving maternal and child nutrition to prevent the development of chronic diseases such as bone diseases later in life.