Comparative 25-OH-vitamin D level in institutionalized women older than 65 years from two cities in Spain and Argentina having a similar solar radiation index.
OBJECTIVE
The present study evaluated and compared vitamin D nutritional status and calcium-phosphorus metabolism in institutionalized women >65 y from two cities that have a similar sun irradiation index (heliophany).


METHODS
The study was carried out in women living in similar social-status institutions from geographic cities having a similar solar radiation index (Lleida, Spain, n=49, and suburban Buenos Aires, Argentina [BA], n=48) at the end of summer.


RESULTS
Fish consumption was higher in the Lleida group, as was red-meat consumption in the BA group. In both groups mean calcium intake was 800 mg/d. The daily intake of vitamin D was higher in the BA group (P<0.001). A total of 90% in Lleida and 86% in BA had 25-hydroxyvitamin D (25OHD) levels <20 ng/mL. A significant inverse correlation between individual 25OHD and parathyroid hormone (PTH) levels was observed in the two groups of women (r=-0.329, P=0.035). PTH levels >100 pg/mL were found in 24% and 20% of women in Lleida and BA, respectively. There was a marked increase in carboxy-terminal telopeptide cross-links of type I collagen levels and a decrease in 25OHD with an increase in PTH levels (P<0.05). Conversely, bone alkaline phosphatase increased significantly only when the PTH concentration duplicated the reference range.


CONCLUSIONS
Even at the end of summer, vitamin D deficiency/insufficiency was prevalent in the two studied institutionalized elderly women. In the narrow range of the dietary calcium intake (close to 800 mg/d) of both studied groups, secondary hyperparathyroidism was absent when 25OHD levels were >17 ng/dL, indicating changes in the regulation control of serum PTH and consequently the changes in this threshold. As a result, vitamin D deficiency must be reversed to avoid the increment in bone turnover and to ensure the endocrine and paracrine functions of vitamin D for overall health and well-being.
Portela
María Luz Pita Martin
ML
Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
Mónico
Amália
A
Barahona
Antonieta
A
Dupraz
Hernan
H
Sol Gonzales-Chaves
Macarena Maria
MM
Zeni
Susana Noemi
SN
D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000378:metabolism; D001118:Argentina / Q000453:epidemiology; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000008:administration & dosage*; D002136:Calcium, Dietary / Q000008:administration & dosage; D002947:Cities; D003094:Collagen / Q000378:metabolism; D004032:Diet; D005260:Female; D006801:Humans; D010281:Parathyroid Hormone / Q000097:blood*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D013472:Sunlight; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D014815:Vitamins / Q000008:administration & dosage / Q000097:blood
D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; D003094:Collagen; C104450:25-hydroxyvitamin D; D000469:Alkaline Phosphatase; D002118:Calcium