Paradoxical Response of Parathyroid Hormone to Vitamin D-Calcium Supplementation in Indian Children.

OBJECTIVES: To investigate the effect of oral vitamin D-calcium supplementation on serum intact parathyroid hormone (PTH), calcium, phosphorous, and alkaline phosphatase (ALK-P) concentrations in children with habitually low calcium intakes. STUDY DESIGN: In this follow-up study to a randomized controlled trial that aimed to assess the effect of vitamin D-calcium supplementation on immunity, data related to dietary intake, anthropometry, and biochemistry [serum 25(OH)D and bone profile] were collected from 178 children-79 in the vitamin D group and 99 in the non-vitamin D group. RESULTS: Dietary calcium to phosphorus intake ratio was 0.4:1. Baseline serum 25(OH)D concentration was 58.2 ± 10.9 nmol/L; 66% children were vitamin D sufficient and none deficient. After supplementation, vitamin D group, compared with the non-vitamin D group, had significantly (P < .05) greater 25(OH)D (83.9 ± 30.1 nmol/L vs 58.3 ± 15.7 nmol/L), significantly greater PTH (6.7 ± 3.6 pmol/L vs 5.5 ± 3.2 pmol/L), and positive correlation (rs = 0.24) between serum 25(OH)D and PTH (vs negative correlation [rs = -0.1] in non-vitamin D group). Mean concentrations of serum bone measures in the vitamin D group were calcium (2.2 ± 0.1 mmol/L), phosphorus (1.7 ± 0.2 mmol/L), and ALK-P (178.7 ± 40.7 IU/L). At follow-up, 1-year post-supplementation, in the vitamin D group, PTH concentrations continued to remain high (but not significantly different from levels at 6 months), with low normal serum calcium, high normal phosphate, and ALK-P in reference range. CONCLUSIONS: In children who are vitamin D sufficient but with habitually low dietary calcium intake, vitamin D-calcium supplementation paradoxically and significantly increased serum PTH concentrations with no apparent effect on other bone biochemistry. Chronic low dietary calcium to phosphorus ratio is likely to have caused this paradoxical response.

Randomized Control Trial Assessing Impact of Increased Sunlight Exposure versus Vitamin D Supplementation on Lipid Profile in Indian Vitamin D Deficient Men.

BACKGROUND: Despite abundance of sunshine in India, Vitamin D deficiency is common and therefore there is an increasing trend toward taking Vitamin D supplements either as prescription medicine or as a nutritional supplement. Studies have suggested that duration of sun exposure may influence serum lipid profile. OBJECTIVES: To study the effect of increased sunlight exposure versus Vitamin D supplementation on Vitamin D status and lipid profile in individuals with Vitamin D deficiency (25-hydroxyvitamin-D [25OHD] <50 nmol/L). DESIGN: A prospective, randomized open-label trial was carried out in apparently healthy Indian men (40-60 years). Based on 25OHD concentrations, individuals were divided into control (>50 nmol/L, n = 50) and intervention (<50 nmol/L, n = 100) groups. Individuals from intervention group were randomly allocated to two groups; either "increased sunlight exposure group" (n = 50, received at least 20 min sunlight exposure to forearms and face between 11 a.m. and 3 p.m. over and above their current exposure) or "cholecalciferol supplement group" (n = 50, received oral cholecalciferol 1000 IU/day). RESULTS: Significant increase in 25OHD concentrations was seen in both intervention groups (P < 0.01). Significant decrease in total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C), and low-density-lipoprotein cholesterol (LDL-C) was seen in individuals with increased sunlight exposure (P < 0.05). Cholecalciferol supplement group showed a significant increase in TC and HDL-C (P < 0.05) and insignificant increase in LDL-C. CONCLUSIONS: Increase in Vitamin D concentrations through sunlight exposure significantly reduced TC, LDL-C, and HDL-C concentrations, and cholecalciferol supplementation increased TC and HDL-C concentrations.

Changes in body composition of Indian lactating women: a longitudinal study.

BACKGROUND AND OBJECTIVES: Lactation places enormous demands on maternal bone mineral homeostasis. Indian middle class women (MSC) consume energy dense food supplements to meet these demands post-partum (PP) along with restricted physical activity (PA). Effects of these changes on body composition (BC) of PP women have not been studied. To examine longitudinal changes in: a) bone mineral density (BMD) at total body (TB), AP-spine (APS) and dual femur neck regions (DF) b) BC by body weight, lean mass, fat mass using dual energy X-ray absorptiometry (DXA) at baseline, 6-months and 1-year in urban MSC women. METHODS AND STUDY DESIGN: 76-primi-parous (28±3.2 yrs) randomly selected PP women (<7-days) were studied; 70 reassessed at 6- months and 42 1-yr PP. Data on anthropometry, BC, BMD at TB, APS and DF by DXA collected (baseline, 6- months, 1-yr PP). RESULTS: Weight, waist and body mass index (BMI) decreased both at 6-month and 1-yr PP with respect to baseline (p<0.05). BC changes showed increase in android fat % at 1-yr by 10% over baseline (p<0.05). BMD with initial decline at 6-months (-2.8%, -2.3% and -2.3% respectively) recovered partially by 1-yr (+2.5% +1.2% and +4.8% respectively) at DF and TB with complete recovery at APS (p<0.05). CONCLUSION: These urban relatively sedentary MSC women consumed fat rich food PP with higher android fat retention and partial recovery of BMD at DF and TB at 1-year. Modifications in activity and dietary nutrient intakes may be necessary to prevent cardiovascular and bone health related risks.

Effect of micronutrient supplementation on height velocity of underprivileged girls in comparison with un-supplemented healthy controls.

The aim of this study was to investigate the effect of 1-year micronutrient supplementation on the height velocity of underprivileged premenarchal girls in comparison with the natural growth of apparently healthy girls from an affluent class. A 1-year cluster-randomisation intervention trial was conducted in 119 premenarchal girls (8-12 years) from two schools catering to the lower socioeconomic strata (LSES) in Pune, India. Three classes of age-matched girls were randomly allocated to any one of the three intervention groups: (i) Ca+MZn+D group (C1: zinc, 15 mg/day+multivitamins; calcium, 500 mg/day; vitamin D, 30,000 IU/3 months); (ii) Ca+D group (C2: calcium, 500 mg/day; vitamin D, 30,000 IU/3 months); and (iii) M+D group (C3: multivitamins; vitamin D, 30,000 IU/3 months). Height, weight, and Tanner stage were assessed at baseline and endline. A total of 119 age-matched, apparently healthy school girls from a higher socioeconomic group (HSES) were assessed for their growth after 1 year without any supplementation. At baseline, mean height-for-age Z-scores and weight-for-age Z-scores by Indian references were >-2 in 99% of HSES girls and 28% of LSES girls had height-for-age Z-scores <-2. Post-intervention, increase in height-for-age Z-scores adjusted for Tanner stage was significantly higher in the Ca+MZn+D group (0.32±0.06) than in the respective age-matched controls (C1 group) (-0.02±0.05) (p<0.05) as well as in both the Ca+D group (0.18±0.06) and the M+D group (0.14±0.04) (p<0.05). After adjusting for Tanner stage, height velocity was significantly higher for the Ca+MZn+D group (6.7±0.4 cm/year) than for the M+D group (6.1±0.2), Ca+D group (5.6±0.5) as well as age-matched controls (C1 group) (5.0±0.3) (p<0.05). Supplementation with calcium+vitamin D, zinc and multivitamins may be effective in improving stature in underprivileged Indian premenarchal girls.

Use of vitamin D in various disorders.

Approximately 1 billion people worldwide have been identified as vitamin D deficient in the 21st century, and the number is on the rise; non-classical actions of vitamin D were initially recognized around 30 y ago when receptors for vitamin D were detected in neoplastic cells lines. The aim of this review is to provide a brief overview of the non-classical actions of vitamin D. Reports describing the associations of non skeletal actions of vitamin D, especially pertaining to the immune system, inflammatory disorders, cancers and cardiovascular disease have been summarized in this paper. Reports support a role for the active form of vitamin D in mediating normal function of both the innate and adaptive immune systems. Studies also suggest a link between vitamin D deficiency and autoimmune diseases, such as rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus and type 1 diabetes. There is believed to be an inverse association between serum 25-hydroxyvitamin D concentrations and the incidence of colorectal cancer, sporadic colorectal adenoma and breast cancer. Vitamin D deficiency has been linked with various cardiovascular diseases such as hypertension, myocardial infarction, and stroke. Several epidemiological and genetic studies suggest a strong association between vitamin D and non skeletal acute and chronic disorders. However, currently, robust clinical data are still lacking to support raising intake requirements and target vitamin D plasma levels. Nonetheless, the high prevalence of vitamin D deficiency is alarming and requires implementation of clear supplementation guidelines.

Diet and exercise intervention, with special reference to micronutrients, reduces cardiometabolic risk in overweight children.

OBJECTIVE: To study the effect of lifestyle intervention in the presence of multivitamin-zinc supplementation in improving the cardiometabolic status of overweight children. MATERIALS AND METHODS: Data were evaluated in 74 overweight children (11.3 ± 2.9 years) randomly assigned to three groups of intervention for 4 months as follows: group A: diet-exercise counseling with multivitamin-zinc supplementation; group B: diet-exercise counseling; and group C: placebo. Anthropometric, biochemical, carotid arterial and lifestyle parameters were assessed. RESULTS: Lifestyle counseling resulted in significant reduction in inactivity, energy and fat intakes and increase in micronutrient density of diets and physical activity in groups A and B in comparison to group C. Percent decline in body fat was more in group A than in groups B and C. Percent change in triglycerides (-13.7%) was significantly higher in group A than in groups B (-5.9%) and C (5.7%). Pulse wave velocity and elasticity modulus reduced and arterial compliance improved significantly in group A than in group B. CONCLUSION: Multivitamin-zinc supplementation with lifestyle intervention has a positive effect of on the cardiometabolic status of overweight children.

Calcium bioavailability from a fortified cereal-legume snack (laddoo).

OBJECTIVE: Calcium intakes in underprivileged Indian children are often low. Improving calcium intake fortification of indigenous foods may be a viable strategy. The aim of this study was to evaluate calcium absorption, as judged by an acute increase in serum ionized calcium concentration, after ingestion of a calcium-fortified cereal-legume snack (laddoo). METHODS: Three groups of eight children (8-12 y old) with low habitual dietary calcium intake were recruited for the study. After an overnight fast, a calcium-fortified (500 mg of calcium carbonate) cereal-legume snack (laddoo) was given to group A, a similar but non-fortified snack was given to group B, and group C received calcium carbonate (500 mg) alone. Serum concentrations of ionized calcium and intact parathyroid hormone were measured at 0, 1, 2, 3, 4, and 5 h. RESULTS: In group A, a peak of 6% above baseline was observed at 1 h in serum ionized calcium, whereas group C showed a peak of 5.5% at 4 h and group B showed a small increase of 1.8% at 1 h. The change in area under curve of groups A and C were of similar order (4.6 and 5.5, respectively), whereas that of group B was significantly lower (0.82). Serum parathyroid hormone was lowest at 2 h in groups A and B and at 3 h in group C. CONCLUSION: The fortified cereal-legume laddoo may act as a novel vehicle for increasing calcium intake in children.

The accrual of bone mass during childhood and puberty.

PURPOSE OF REVIEW: To assess factors that influence the tempo of bone mass accrual with emphasis on obesity, exercise, and nutritional factors. RECENT FINDINGS: The prevalence of childhood obesity has increased dramatically throughout the world. Recent studies suggest that adiposity may be detrimental to development of bone strength parameters, and bone mass accrual during growth. Weight-bearing exercise during prepubertal and peripubertal period appears to enhance bone strength parameters. Maternal ultraviolet B radiation exposure and vitamin D status has been shown to have a positive effect on neonatal bone status, which appears to track up to the prepubertal period. Administration of vitamin D with or without calcium, but not calcium alone, during the prepubertal period might be an important 'window' for improving skeletal mineralization. SUMMARY: Obesity in children appears to be detrimental to development of bone strength parameters and bone mass accrual. Weight-bearing exercise during prepubertal and peripubertal period and vitamin D supplementation during pregnancy, infancy, and peripubertal period might be important for bone mass accrual. However, adequately powered randomized controlled trials with follow-up into adulthood are needed to determine if these interventions improve the tempo of bone mass accrual.

Vitamin D supplementation and bone mass accrual in underprivileged adolescent Indian girls.

Vitamin D deficiency is common among children and adolescents in India, in spite of abundant sunshine. We conducted a pilot; double blind randomised controlled trial to investigate the effect of vitamin D supplementation on bone mineral content in underprivileged adolescent girls, in Pune, India. Fifty post-menarcheal girls aged 14 to 15 years were randomised to receive 300,000 IU (7.5 mg) of ergocalciferol or placebo orally, 4 times/year. All participants received 250 mg elemental calcium (calcium carbonate) daily. Outcome measures included change in serum 25-hydroxyvitamin D, size adjusted bone area and bone mineral content at total body and lumbar spine. Post supplementation, the median serum concentration of 25-hydroxyvitamin D was 75.2 (64.2-85.5) nmol/L in the intervention group and 28.1 (16.7-34.0) nmol/L in the placebo group. Increment in bone outcome measures was not different in the two groups. However, there was a positive effect of intervention in the size adjusted total body bone area (p<0.05), total body bone mineral content (p<0.05) and lumbar spine bone mineral content (p<0.05), and positive trend in lumbar spine bone area (p=0.07) in girls who were within 2 years of menarche. We conclude that vitamin D supplementation did not have a beneficial effect on skeletal mineralization in girls who were more than 2 years post menarcheal. However, there was a significant positive effect of the intervention on size adjusted total body and lumbar spine bone mineral content and a positive trend in lumbar spine bone area, in girls who were <= 2 years of menarche.