to fulfill the calcium requirements (25, 35, 41, 42, 44). This relationship which can be
extrapolated to the diet, i.e., this protective function of PTH, may be activated when
calcium and vitamin D are deficient in the diet, since both proved to be negatively
related to PTH in our study (Graph 3).
A positive and significant correlation was found between calcium and dietary
vitamin D, also found in the study by Salamoun et al. 2005 (18) (Graph 3). However,
besides calcium, dietary vitamin D was only correlated with dietary phosphorus,
possibly because they are from similar food sources (source foods for phosphorus:
cheese, egg yolk, milk, cabbage, fish, poultry, whole cereals, vegetables, chestnuts, and
for vitamin D: egg yolk, liver, butter, fish) (45, 46).
Also, it has been evaluated the influence of the vitamin D receptor gene (VDR) in
skeleton turnover, cell growth and differentiation in several vital organs and various
other important metabolic pathways (4, 47). In the study by Morrison et al. 1992, a
relationship was observed between this gene and the osteocalcin gene, besides less bone
density in patients with polymorphism in the VDR, suggesting that it is possible that
different polymorphisms in VDR may result in minimal differences in the dietary
recommendation for calcium, and that these recommendations may vary in different
populations (48). Lorentzon et al. 2000, found similar results, i.e,, an association
between the polymorphism of VDR with short stature at birth, short final stature and
less bone mineral density (49). Furthermore, recent studies such as that by Demplfe et
al. 2006, also verified this association between the polymorphism of the nucleotide in
the gene of VDR and SS; they found that this variation could be responsible for
approximately 34% of the cases of idiopathic SS studied (4). We cannot rule out that
this polymorphism could be the cause of short stature in part of our sample, because the
VDR levels are regulated by several factors including hormones, growth factors, as well