Vitamin D status and its relationship with bone mineral density in healthy Asian Indians.
ABSTRACT Synthesis of vitamin D takes place in the skin under the effect of sunlight. The Indian subcontinent is situated between 8.4 degrees N and 37.6 degrees N latitudes and has adequate sunshine throughout the year. Thus, it has been presumed that Indians are vitamin D sufficient. We measured serum 25-hydroxy vitamin D [25(OH)D] ( n=92) and 1,25-dihydroxy vitamin D [1, 25(OH)(2)D] ( n=65) levels in healthy hospital staff, using (125)I radioimmunoassay. Serum intact parathyroid hormone (PTH) concentration was estimated by immunoradiometric assay. Bone mineral density was estimated using a dual energy X-ray absorptiometer (Hologic QDR 4500A). Using a serum 25(OH)D level of 15 ng/ml as a cutoff, 66.3% (61/92) of the subjects were found to be vitamin D deficient. Of these, 20.6% (19/92) subjects had severe vitamin D deficiency (<5 ng/ml), 27.2% (25/92) had moderate vitamin D deficiency (5-9.9 ng/ml), while 18.5% (17/92) had mild vitamin D deficiency (10-14.9 ng/ml). When a serum 25(OH)D level of 20 ng/ml was used as a cutoff, 78.3% subjects were diagnosed to be vitamin D deficient/insufficient. The serum 1,25(OH)(2)D level was within the normal range (40.6+/-20.1 pg/ml; mean +/- SD). Mean (+/-SD) serum intact PTH, estimated in a limited number of subjects (n=15), was 72.3 (+/-21.0) pg/ml (range 36-100 pg/ml). There was a significant correlation between daily sun exposure and 25(OH)D levels (r=0.731, P<0.001). The serum 25(OH)D level correlated with BMD at the femoral neck and Ward's triangle (r=0.50, P=0.020 and r=0.46, P=0.037, respectively). Our findings show that vitamin D deficiency is common in urban north Indian hospital staff. The possible reasons include inadequate sunlight exposure and skin pigmentation in Indians. The serum 1,25(OH)(2)D level is not a good indicator of vitamin D deficiency. A low serum 25(OH)D level is possibly one of the reasons for lower bone mineral density among Indians.
[show abstract] [hide abstract]
ABSTRACT: It is well established that low levels of 25(OH) Vitamin D (<30 ng/dL) are a common finding world over, affecting over a billion of the global population. Our primary objective was to determine the prevalence of vitamin D deficiency and insufficiency in the asymptomatic adult population of Karachi, Pakistan and the demographic, nutritional and co-morbidity characteristics associated with serum vitamin D levels. A cross-sectional population survey was conducted at two spaced out densely populated areas of the city. Serum levels of 25OH vitamin D were measured and GFR as renal function was assessed by using 4 variable MDRD formula. Our sample of 300 had a median age of 48(interquartile range 38-55) years. The median level of serum vitamin D was 18.8 (IQ range 12.65-24.62) ng/dL. A total of 253 (84.3%) respondents had low levels (<30 ng/dL) of 25OH vitamin D. Serum PTH and vitamin D were negatively correlated (r = -0.176, p = 0.001). The median PTH in the vitamin D sufficiency group was 38.4 (IQ range28.0-48.8)pg/mL compared with 44.4 (IQ range 34.3-56.8) pg/mL in the deficiency group (p = 0.011).The median serum calcium level in the sample was 9.46(IQ range 9.18-9.68) ng/dL. Low serum levels of vitamin D were not associated with hypertension (p = 0.771) or with an elevated spot blood pressure (p = 0.164).In our sample 75(26%) respondents had an eGFR corresponding to stage 2 and stage 3 CKD. There was no significant correlation between levels of vitamin D and eGFR (r = -0.127, p-value = 0.277). Respondents using daily vitamin D supplements had higher 25 OH vitamin D levels (p-value = 0.021). We observed a high proportion of the asymptomatic adult population having low levels of vitamin D and subclinical deterioration of eGFR. The specific cause(s) for this observed high prevalence of low 25OH vitamin D levels are not clear and need to be investigated further upon.PLoS ONE 01/2012; 7(3):e33452. · 4.09 Impact Factor
[show abstract] [hide abstract]
ABSTRACT: Osteoporosis is a systemic skeletal disease characterized by reduced bone mineral density, disrupted bone microarchitecture and alterations in the amount and variety of proteins in bones. Bone turnover is a very complex process, depending on genetic and non genetic factors, such as diet, lifestyle or air pollution. The aim of the study was to explore genetic and environmental risk factors that contribute to osteoporosis by quantifying several factors related to bone mineral density. We assessed family history, vitamin D status, bone mineral density in subjects seeking advice on osteoporosis. Air pollution data were also obtained. Average concentrations of NO2 and particulate matter PM10 were calculated. Due to their synergistic effect on the organism the maximum permissible concentration calculated for all air pollutants was exceeded. In our study total body bone mineral density was inversely associated with indicators of air pollution. The prevalence of vitamin D depletion was 64.76%. Genetic contribution to the etiology of osteoporosis was revealed by the positive family history for 36% affected subjects. Air pollution and vitamin D deficiency have a negative impact on bone mineral homeostasis.Analele Universitatii din Oradea, Fascicula Biologie. 01/2010;
Indian Journal of Clinical Biochemistry 10/2011; 26(4):428-9.