By Jim Sayih

In a population where fitness is a priority and high performance is a goal, references to body composition are common. Athletes prioritize the regular evaluation of body fat vs. muscle mass to establish a most effective training program. Yet this emphasis on muscle and fat, although important, fails to address the importance of skeletal health. Evaluations of bone density, the frequency and healing rate of fractures, and dietary calcium intake are far less common.

Let’s clear up a couple of things before looking at this in more detail. First of all, poor bone status is not limited to elderly women suffering from osteoporosis. Dietary inadequacies can affect the bones regardless of gender or age. Secondly, bone is not an inert mass that develops in youth and stays constant throughout adult life. Rather, it’s an active living tissue that commands constant flow and exchange of nutrients throughout the day. So obviously bone is affected by our lifestyle.

Bone is indeed a specialized form of connective tissue. Peak bone growth, or mass, is genetically determined, but is also effected by diet, physical activity and hormonal status. Modeling refers to the addition of bone to surfaces undergoing high loading or strain, primarily during growth. Remodeling is the process by which fatigue-damaged bone is replaced by new bone. The ability of the bone to adapt to different types of exercise and "load" is quite amazing! Exercise in general, more specifically, weight-bearing exercise tends to enhance this remodeling process and strengthens the bone.

One example of this is found in a study of 7-9 year old elite gymnasts who at any given body weight had higher bone density as compared to swimmers. Tennis and squash players, ballet dancers and basketball players all tend to rank high in bone health. Again, that weight-bearing load demands the body’s response.

This sounds great!! But if the basic building materials are not available, then this process is literally stopped in its tracks. Yes, that major building block would be calcium. Activity without calcium would not be of benefit to bone, nor would calcium without activity be helpful.

Calcium is the most abundant mineral in the body. The bones and teeth contain 99% of the body’s calcium. The remaining 1-% circulates in the bloodstream. Calcium is critical for nerve impulse conduction, heart function, muscle contraction, and the operation of certain enzymes. When the supply of calcium in the blood is too low, the body actually withdraws needed calcium from the bones.

Osteoporosis, a disease reflecting a decrease in bone mass and susceptibility to fractures, affects an estimated 24 million people. Because of their lower bone mass, women are more susceptible to this "silent disease." The current recommendations for calcium are 800 milligrams per day for adult’s men and women, but the current RDA for women up to age 24 is 1,200 mg per day. The research field is hot with studies looking at the proper levels of dietary intake and effects of calcium supplementation.

A recent study looked at over 10,000 French subjects, ranging in age from 7 to 50, to examine the relationship between physical activity and dietary intake of calcium. The average intake was 1242 mg with 50% of the population taking in less than 1000 mg per day. Consumption decreased with age and was lower in females compared to males. (This correlates with patterns in the U.S. population, where half of all adult women consume less than 500 mg of calcium per day.)

The subjects who trained in individual endurance sports like triathlon; biking and road running had a lower calcium intake than subjects who trained in team sports like volleyball, handball or basketball. Calcium intake was higher in elite athletes, irrespective of their level or training intensity attained in a given sport. Psychological and sociological profiles may well be of influence in these differences.

Why is it so difficult to meet this calcium challenge?? Perhaps because we stop seeing the importance of calcium once we reach adult height. It’s as if we think that once the skeletal is formed, it’s stable. The other obstacle to overcome is the endless array of drink and food choices in our country that quench your thirst or satisfy hunger. The old decision of coffee, tea, or milk has been replaced with a plethora of concoctions with every taste, color and caloric content imaginable. The fear of fat has also moved many Americans away from dairy sources. And although low-fat choices still provide abundant calcium, quite often the taste isn’t appealing.

Dairy products represent the best sources of calcium. Skim or low-fat versions of milk, yogurt or cheese provide the same amount of calcium as the regular choices. Broccoli and greens (kale, collard, turnip and mustard) are good sources of calcium without any fat. Tofu processed with calcium sulfate is also a good non-fat calcium provider. Manufacturers that have fortified orange juice with calcium are also looking to help you build those bones.

Many factors determine how much calcium the body absorbs. High intakes of protein, sodium, and caffeine interfere with calcium retention. Excess alcohol intake also has detrimental effects on bone mass.

If the diet is weak in the calcium count, then you may opt for a supplement. All forms of calcium in supplements are well absorbed. The differences: Calcium citrate malate is best absorbed, but calcium carbonate is the most concentrated, so you get more per tablet. If it’s convenient, take your calcium supplements with a meal, ideally in doses of 500 mg or less. When in doubt of the situation, check with your physician or dietitian.

And finally, be grateful for our hot sun! Exposure to sunlight is a primary source of vitamin D, which aids the absorption of calcium and builds bone. Exposing your non-sunscreened hands, face, and arms for 10 to 15 minutes, two to three times a week between 8 a.m. and 4 p.m. seems to do the trick. Piece of cake for most of us!

Dedication to a lifetime of adequate calcium intake and exercise will give you the skeletal strength to stand above the rest!!!