As improved care options and, hopefully, treatment advances extend the life expectancy of
ALS patients, more of us will need to address long term problems such as osteoporosis. As we
enter middle age, we are constantly reminded of the need for calcium to prevent osteoporosis.
Osteoporosis occurs in immobilized people as well as in older people. The ALS patient needs to
understand the processes at work because the standard treatments for age-related osteoporosis
are not helpful and potentially harmful for the disabled.
Bones and Calcium
Bone is living tissue that is continually being broken down and replaced. Up to age 30, more
bone is formed than lost, but after age 30 that changes. Although we continue to replace bone,
we have an overall net loss of bone mass. That loss is normally very gradual but is sped up by
some factors. It is affected by race, heredity, body type, age, and especially by gender. Women
have more bone loss than men because of hormonal changes that occur with menopause. Diet and
smoking have an effect on bone loss, and lack of exposure to sunlight can prevent absorption of
calcium from the food we eat. Another factor is decreased exercise. That is a small but
important factor for the typical osteoporosis patient but is the major factor for the long term
ALS patient.
The trigger that makes bone absorb calcium and keep itself strong is stress on the bone.
Exercise, especially exercise that involves bearing weight on the bone, stimulates the bone to
absorb calcium and rebuild itself. When we are immobilized, calcium continues to be slowly lost
from the bone in the normal way but is not replaced because the trigger to replace it, exercise,
is gone. In disabled people, the problem is not that we lose bone mass faster, it is that we
fail to replace it. The result is osteoporosis—weak, brittle bones that break more easily.
That is a real problem for ALS patients as we are prone to falls.
For the immobilized patient, there is another problem seldom discussed in the literature on
osteoporosis because it is so oriented to the osteoporosis of aging: The calcium being lost from
the bones and not being reused to rebuild bones but ends up circulating in the blood. Lab tests
of blood calcium will show abnormally high levels. (There may be some cellular problem with
the use of calcium that leads or contributes to the loss of motor neurons, but the high calcium
levels seen in ALS patients is NOT a cause of ALS but a result of the immobility ALS
causes.)
The kidneys will filter out calcium and excrete the excess, but, in time, the kidneys will
get clogged up with calcium. Kidney stones will form and all the problems associated with kidney
stones can occur. This is not uncommon in the general population and it is a very common
problem for spinal cord injured patients. For ALS patients this has rarely been a problem simply
because life expectancy is shorter than the time needed to develop kidney stones. Long term ALS
patients may face this problem, however.
Treatment
Although early diagnosing of osteoporosis is difficult, when a person with ALS shows up in
the Emergency room with a fracture from what should have been a "survivable" fall (one not
causing broken bones) it is logical to assume that there is a significant amount of osteoporosis
present. But what is the proper treatment? This is where the literature leads us (and sometimes
our doctors) astray. Applying standard treatments for osteoporosis to ALS patients may cause
worse problems. The standard treatments are:
Increased dietary intake of calcium. There are two problems with this
treatment for ALS patients. First and most significantly, our problem is not lack of calcium or
even our loss of calcium from the bones, but rather the lack of the trigger to move available
calcium back into the bones. Increasing intake of calcium only leaves more calcium in the
blood. That doesn't help the bones and can cause kidney stones. Second, dairy products are the
biggest source of calcium but dairy products tend to thicken mucus and respiratory secretions.
ALS patients already have enough with choking and gagging and may need to be restricting their
intake of milk and milk products, not increasing it.
Calcium supplements (oral, intravenous, or injected). The problem is the same
as above. We don't need more calcium, we need the trigger to move it back into the bones to
replace normal bone loss.
Sunlight/Vitamin D Oral calcium requires Vitamin D to be absorbed but more
importantly for the ALS patient, Vitamin D, especially D3, helps move calcium into the bones,
making it is a valuable treatment for the ALS patient. The best source of Vitamin D is our own
skin. Sunshine causes the skin to manufacture a substance that our liver turns into Vitamin D.
Just 10-15 minutes of sun 2-3 times a week is all that is required so there is no need to risk
skin cancer!
Although dietary intake of Vitamin D is normally not especially significant, people who can't
get sunshine can increase intake with foods. For decades, our milk has been routinely fortified
with it to prevent rickets, but milk may need to be avoided by ALS patients for the reason
discussed earlier. Some breakfast cereals are fortified with Vit. D (read the label), and
butter and eggs, fatty fish (such as herring, mackerel and salmon) are sources. As a last
resort, Vit. D supplements are available. Don't take more than 400 IU of vitamin D a day unless
prescribed by your doctor. Excess is not excreted so you can overdose. Vitamin D toxicity can
lead to nausea, weight loss, irritability, and formation of calcium deposits in your lungs,
kidneys and soft tissues.
Estrogen Estrogen is the most common drug prescribed to preserve bone mass.
Estrogen has been proven to prevent menopause-related bone loss but it is apparently not useful
in other cases of osteoporosis.
Bisphosphonates Bisphosphonates such as Fosamax and Boniva are now being
prescribed. These are non-hormonal agents that prevent bone from releasing calcium. This
treatment works to alleviate the inability to replace calcium lost from the bone and is
logically a better choice for the ALS patient than treatments that only add calcium to the
bloodstream.
In summary, ALS patients are prone to osteoporosis and the resultant brittle bones, but it
is related to their inability to exercise as much or more than the typical factors of aging.
Blood calcium levels will already be high, and additional calcium won't help and may even be
harmful long term. ALS patients can best combat osteoporosis by getting what exercise they can
(and for us, simply being held up in a standing position is the weight-bearing exercise needed),
and by making certain we have an adequate amount of Vitamin D by getting a little sunshine. If
further treatment is needed, discuss with your doctor whether his proposed treatment that will
get the calcium into the bones, not just into the bloodstream.