Vitamin D status in healthy Indians aged 50 years and above

There is widespread prevalence of vitamin D deficiency from new-born to infancy, childhood and adult male and females (non-pregnant, pregnant and lactating). However, there is limited information of the vitamin D status in elderly Indians.

The study was carried in 1346 healthy subjects more than 50 years of age residing in Delhi, India. These subjects, who were divided in two groups: Group-1 (50-< 65 years) and Group-2 (> or = 65 years), underwent anthropometric, biochemical and hormonal evaluation for vitamin D status Bone mineral density was measured by dual X-ray absorptiometry.

There were 643 males and 703 females, with a mean age of 58.0 +/- 9.5 years (range 50-84 years). Vitamin D deficiency [VDD, serum 25(OH)D levels < 20 ng/ml) was present in 1228 (91.2%) and Vitamin D insufficiency [VDI, serum 25(OH)D levels 20-< 30 ng/ml] in 92 (6.8%). There was no significant difference in prevalence of either VDD or VDI between two age groups and sexes. Serum 25(OH)D levels were negatively correlated with PTH levels (r -0.027, p <0.00001) and BMI (r -0.128, p 0.05). Prevalence of secondary hyperparathyroidism increased from 14.1% to 43.1% from VDI to severe VDD. PTH levels started rising at vitamin D level < 30 ng/ml. However, more than 50% of subjects with severe VDD had PTH levels within normal range. High prevalence of osteopenia (50.2%) and osteoporosis (31.2%) was observed in this population.

Hypovitaminosis D is universal above the age of 50 years in north India. Absence of a PTH response was observed in more than 50% of individuals with VDD, the cause of which merits further evaluation. Normal bone mass was observed in only 18.6% of study subjects.