[Vitamin D status in aged subjects. Study of a Lebanese population]

To evaluate vitamin D status in two subgroups of the Lebanese aged population. To compare results with reference values observed in healthy young volunteers.

Fifty aged institutionalized patients (25 men and 25 women) and 51 aged ambulatory subjects (25 men and 26 women) underwent the following explorations during winter: serum 25-OH vitamin D, parathyroid hormone, corrected serum calcium, phosphorus, creatinine, and alkaline phosphatases and urinary calcium/creatinine. Serum 25-OH vitamin D and urinary calcium/creatinine were also measured in 34 healthy young volunteers.

Serum 25-OH vitamin D levels in 25 ambulatory subjects (49%) and 30 institutionalized patients (60%) were below 10 ng/ml. There was non significant difference in 25-OH vitamin D levels between the ambulatory and institutionalized aged populations, nor between aged women and aged men. Parathyroid hormone, alkaline phosphatases and urinary calcium/creatinine levels were higher in the institutionalized population than in the ambulatory population (p = 0.07; p = 0.0001; p = 0.0001 respectively). Aged women had higher parathyroid hormone and calcium/creatine levels than aged men (p = 0.005; p = 0.005 respectively). Finally, in the young population, 25-OH vitamin D was higher than in the aged institutionalized and ambulatory populations (p = 0.0001 and p = 0.0009 respectively). An inverse non-significant correlation (r = -0.16) was found between parathyroid hormone and 25-OH vitamin D.

Our results show that even in a sunny country like Lebanon, vitamin D deficiency is often observed. The degree of deficiency probably lies between that observed in Europe and the United States. It could be related to low vitamin D diet.