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 speeded 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 is circulated 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 a 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 Oral calcium requires Vitamin D to be absorbed but more importantly for the ALS patient, Vitamin D 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 prevents menopause-related bone loss but it is apparently not useful in other cases of osteoporosis. .
	Biphosphonates Biphosphonates 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 blood stream.

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.