Vitamin D-ascorbic Acid Association in Bone Metabolism 51 



CoHN and Forscher (1962) presented evidence suggesting that lactic acid was 

 the major end-product of glucose metabolism in bone tissue. Goldhaber (1961) 

 showed that oxidative metabolism was necessary for bone resorption while Walker's 



Table 3. Cellular activity and phosphate mobilization 



1. Control 



2. Vitamin D3 deficient 



3. 2 + 44 mg ascorbic acid/kg diet . 



4. 2 + 220 mg ascorbic acid/kg diet. 



' Correlation value. 



- Significant at the 99% confidence level. 



results (1961) Indicated operation of the Krebs cycle in the osteoclast and its inhibi- 

 tion in the osteoblast. These results point to the potential metabolic versatility of the 

 bone cell. Thus, the increased oxidative metabolism exhibited by bone tissue from the 

 vitamin D3 deficient animals could be explained on a basis of an alteration in meta- 

 bolic pathways. An explanation of this response and why dietary ascorbic acid 

 appears to reverse the effect will be of interest in future investigations. 



Summary 



The results of this experiment suggested that both ascorbic acid and vitamin D., 

 were involved in bone cellular metabolism. Little or no correlation was apparent 

 between cell activity and in vitro bone demineralization in either control or vitamin 

 D3 deficient groups; however, the addition of dietary ascorbic acid was associated 

 with a significant degree of relationship between these factors. 



Acknowledgoncnt 



This investigation was supported by Public Health Research grant number: 

 AM-07724-01 from the National Institutes of Health. The author was a member of 

 the Endocrine Section, Colorado State University, Ft. Collins, Colorado, when the 

 above work was conducted. 



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BoRLE, A. B., N. Nichols, and G. Nichols, Jr.: Metabolic studies of bone in vitro. I. Nor- 

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CoHN, D. v., and B. K. Forscher: Aerobic metabolism of glucose by bone. J. biol. Chem. 

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