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DISCUSSION 



Brull: Urinary calcium, as far as I can see, is rather a leakage, and is 

 more or less independent of the rest of the calcimn balance, and much 

 more influenced by diuresis and organic acid metabolism than by any- 

 thing else, except in disease of the parathyroid gland. 



What do you think about senile osteoporosis, when it has gone so far 

 that the vertebrae break down? Do you believe that it is due to lack of 

 intake or do you think there is another factor? 



Nicolaysen: My opinion changes from day to day! I think you just 

 have to do long-term studies. There is material indicating that old 

 osteoporotic men retain calcium remarkably well, but that may again 

 be over shorter periods of time. We may have a certain capacity for 

 repair but not a complete one; but it may be that the periods of observa- 

 tion are not long enough. 



Brull: I have done many calcium balances, and I have now some 

 doubt about the value of them at all. If you take a case of osteoporosis, 

 and do the calcium balance, you very often find normal requirements. 

 If you investigate their background, you find that some people who 

 become osteoporotic have had a normal calcium intake, and others, 

 who have no disease, had a low calcium intake. Then there is the 

 striking fact that when you take a patient who has just a normal 

 balance but who has osteoporosis, and you give him very small doses of 

 follicular hormone, there are enormous changes in calcium balance. 

 This suggests another origin of osteoporosis. 



Nicolaysen: Well, in ordinary persons you can introduce new matrix 

 with the aid of sex hormones, you can force calcium deposition. 



Brull: You mentioned the problem of the requirement of vitamin D 

 in adults and old people. As far as we could see the requirement of 

 vitamin D in adults and old people is about 3-4 /xg./day. 



Nicolaysen: I agree with you that they need vitamin D, but I am not 

 sure how much they need; I think that remains to be discovered. 



Brull: There is a very sensitive method to find it out, and that is by 

 the determination of the proportion of phosphorus in the faeces and urine. 



