All About Bone Health

Your Skeleton is Your Christmas Tree

I want you to think of your skeleton as a bank of calcium.  Why do you need a bank of calcium?  It is because everything that happens with cell to cell communication in our bodies is essentially electrical and mediated by calcium ions. If you don’t have enough calcium ions the electrical system in your body won’t work.  The human body relies on a stable source of calcium ions and takes those ions when it needs it from the calcium bank which is your skeleton. Everything needs a steady level of calcium ions in the serum or you die. The heart, lungs, kidneys, liver, the brain, and every other organ relentlessly take whatever calcium they need from your skeleton, the bank.  Sometimes the bank gets overdrawn and then the skeleton fails.  I liken this to having a box full of Christmas tree ornaments, your heart, your kidneys, your brain, etc. Your organs are there and healthy but if you don’t have a skeleton, i.e. Christmas tree, on which to hang your ornaments, there won’t be any Christmas.  So, we need to think about the Christmas tree as well the ornaments.

The Christmas tree, your skeleton, grows rapidly and reaches maturity about the age of 20, a little earlier for girls than boys.  By 22 the skeleton is fully formed.  Very few people add bone mass beyond this age and most begin to deplete their skeleton from that age forward.  To truly treat osteoporosis, the loss of bone, all you need to do is return the clock back to when you were younger than 22.  It might also be convenient to pick better parents. Then we can solve a lot of osteoporosis.  Unfortunately, “Back to The Future” is a movie and not part of your HMO benefits.

How to Build Bone

How to build bone?  The best answer is to get outside and do weight bearing exercise over the course of your life. Walking and weight training are good for your skeleton.  The bone is a living organ. We make it and we dissolve it over and over again.  We can modify the process of bone loss which goes along with aging.  If we can interfere with the back side of the process, resorbing it, then theoretically we can build up bone.  To go back to the bone bank analogy, think of the difference between a checking account and a certificate of deposit.  With a certificate of deposit, you put the money in but it’s more difficult to take it out.  That’s what happens with medications like Fosamax and Boniva.  We make the bone difficult to resorb and therefore make withdrawals from the bone bank more difficult. This works to some extent but only for about 2 years.  The problem is the bone that is built up is not properly repaired and then you can end up with a new kind of fracture.  There are other ways of messing with your physiology but many of them have significant side effects as well.  For instance, we take from the world of cancer treatment medications and apply them in lesser doses for osteoporosis.  Virtually all of cancer treatment severely decimates the skeleton and so most cancer regimens use very powerful bone building chemicals to undo the damage of the poison.  Unfortunately, chemotherapy is extremely destructive to healthy tissue as well as cancer including the skeleton.

Calcium and Vitamin D

Calcium intake in a normal diet is about 200mgs per day. That is fine but what matters most is absorption. You can consume all the calcium you want but you will not take it into your body without vitamin D. Vitamin D comes in several forms.  It needs to be pre-activated by healthy kidneys and then it needs to be activated by the skin and the eyes.  While we are rightfully concerned about skin cancer, we overdo it with sunglasses, hats, and sunscreen which precipitates widespread vitamin D deficiency.  For instance, if you spend about 20 minutes in the sun without a shirt on, you will absorb 10,000 international units of vitamin D.  Up until recently the recommended daily intake of vitamin D was 200 international units and has recently been increased to 400 international units.  I would propose that if our skin is capable of giving us 10,000 international units of vitamin D in 20 minutes, there is a very high likelihood that we need more than 400 international units of vitamin D to be healthy. There is increasing evidence that vitamin D deficiency is increasing rapidly in our population.  In the early 20th century, we artificially added vitamin D to milk in order to treat a skeletal disorder known as rickets that was occurring disproportionately in the central part of the country where there was little or no fresh fish consumption.  Since that part of the country was dairy country, the best way to get vitamin D in the population to treat rickets was to add it to milk. Currently we should probably consider adding vitamin D to soft drinks as its consumption eclipses milk. Vitamin D is essential to absorbing calcium

Medicines Effects on Bones

A medical treatment that is highly destructive to the skeleton is seizure treatment.  Seizures are an electrical phenomenon of the brain and virtually every medication, including Dilantin and Tegretol, used to treat seizures destroy the skeleton over time.  If I had my way I would aggressively treat the skeleton of every patient receiving anti-seizure medications, but sadly this is not on the radar screen of neurologists. They are focused on stopping further seizures. There is also evidence that long-term use of steroids and of many stomach medications that contain omeprazole such as Prilosec and Zegreid and other H2 blockers such as Pepcid, Tagamet and Zantac can have minor effects on bone density.

Opinion pendulums swing fairly dramatically in the world of medicine, for hormone replacement therapy (HRT) and then against it, for sun exposure and then against it and then for it again. Both HRT and sun are good for bones. It is a mistake to think that science only moves forward.  There are significant regressions and many times major treatments and thinking take decades to be identified and corrected.  One must always question the motivation of those putting forward absolutes that may involve an unseen profit or simply be “‘silo” thinking.

The truth is that there is a lot of soft bone out there that is going to become a significant health risk as we all age. There is no quick fix to undo 60 or 70 years of bone resorption.  Certainly, there is no panacea in calcium and vitamin D therapy.  Fosamax, Boniva and Evista are all Bis Phosphanates and do temporarily seemed to halt bone resorption but can be associated with a whole new category of long bone fractures.  Hormone therapies such as calcitonin are helpful.  Intravenous treatment with medications like Reclast have great promise.  None of these therapies are successful without adequate calcium and vitamin D. Without a doubt increasing weight bearing activity is the best treatment available.  Bone grows along the axis of weight bearing, which is defined by Wolff’s Law. Julius Wolff was a German surgeon in the 19th century who found that bone in a healthy person will become stronger and denser in response to stress. This is so clear that we can actually apply an electrical signal to long bones and cause them to grow.  This was discovered by measuring the electrical signal around bones that had weight applied to them and noticing an inductance signal.  By reversing the process, we can actually induce bone growth.  Since bone is a naturally replenishing living organ in the body, we are able to modify the mix of bone turnover, production and resorption.

Bone Density Testing

Bone densitometry testing is notoriously inaccurate.  It’s not a great test for osteoporosis or the predicting of fractures. It is, however, a pretty good mechanism for monitoring whether you are getting better or worse.  If a treatment plan for your skeleton has been initiated, bone densitometry at the beginning and end of it is probably a good idea as long as you go to the same machine.  Accuracy across different machines has been shown to be very non-reproducible.  For instance, if you have a bone densitometry test that says you do not have osteoporosis, but you have gotten an inch shorter than you use to be or you have had compression fractures in your spine, a shoulder fracture or a wrist fracture, then you have osteoporosis regardless of the official reading of the bone densitometry test.  You need to be treated for bone loss.  It is okay to monitor your progress with the densitometry test but it is a lousy diagnostic tool although it is heavily marketed otherwise.

Conclusions

Bone health is something we should be concerned about our entire lives.  As children, we need to get away from the video games and run outside in the sunshine to build our bone bank. As adults, we need to get out of our chairs and go for a walk so our bank keeps a positive balance. If you are put on any medicine indefinitely, ask your doctor if there are any long-term effects on your bones so you can aggressively treat bone loss.

Having said all of this, I would be remiss if I did not note once again that there are significant genetic predispositions to osteoporosis.  Some people just picked the wrong parents.  Being of northern European descent is one of the big ones. I would caution you against too many Google searches in the absence of consulting with a physician with a broader understanding of the problem and physiology. I was cautioned in my early years of being a doctor that there were very few people available who truly understood the physiology of calcium in the lifecycle of bones.  All that has improved dramatically over the last 35 years, but there is still a lot to be learned from many of our previous misunderstandings. Stay tuned!