Determinants of vitamin D supplementation among older adults and its effect on 25(OH)D levels according to bone mineral density status.

INTRODUCTION: Background: although supplementation with vitamin D has been reported as a main determinant of 25-hydroxyvitamin D status [25(OH)D] levels, there are limited data in regard to the factors associated with vitamin D supplementation in older adults. Aims: to examine the characteristics of participants associated with vitamin D supplement use and its effect on 25(OH)D concentrations according to bone mineral density (BMD). Methods: the present analysis was based on data from participants aged 60 years and older in the National Health and Nutrition Examination Survey. Logistic regression models were created to examine the demographic, lifestyle, and health characteristics associated with vitamin D supplementation. Moreover, general linear models were assembled to assess the effect of vitamin D supplement doses on 25(OH)D concentrations according to BMD status. Results: of 5,204 participants, 45.3% reported taking vitamin D supplements, at least 400 IU per day. Overall, women, non-Hispanic whites, college education, former smokers, physical activity, and > 2 comorbidities were variables significantly associated with increased odds of taking vitamin D supplements. Notably, among subjects with osteoporosis, those taking vitamin D supplements between 400 and 800 IU per day had on average 20.7 nmol/L higher 25(OH)D concentrations compared with their non-user counterparts. Conclusions: demographic and healthy lifestyle characteristics are the main determinants of vitamin D supplement use among older adults. Moreover, even among subjects with low bone mass, vitamin D supplements between 400 and 800 IU per day are adequate to reach sufficient 25(OH)D concentrations.

INTRODUCCIÓN: Antecedentes: si bien la suplementación con vitamina D es un determinante principal de los niveles séricos de 25-hidroxivitamina D [25(OH)D], pocos estudios han descrito los factores determinantes del uso de suplementos de vitamina D en los adultos mayores. Objetivos: examinar los factores determinantes del uso de suplementos de vitamina D y su efecto en los niveles de 25(OH)D según la densidad ósea. Métodos: el presente análisis se basó en datos de participantes de 60 años o más en la Encuesta Nacional de Examen de Salud y Nutrición de EUA. Se crearon modelos de regresión logística para examinar las características demográficas, de estilo de vida y de salud asociadas al uso de suplementos de vitamina D. Además, se usaron modelos lineales generales para evaluar, según la densidad ósea, el efecto de la suplementación de vitamina D en las concentraciones de 25(OH)D. Resultados: de 5204 sujetos, el 45,3% informaron que tomaban suplementos de vitamina D, al menos 400 UI por día. En general, las mujeres, los blancos no hispanoamericanos, la educación universitaria, ser exfumador, la actividad física y > 2 comorbilidades fueron características asociadas al aumento de las probabilidades de tomar suplementos de vitamina D. En particular, entre los sujetos con osteoporosis, aquellos que tomaron suplementos de vitamina D en dosis de entre 400 y 800 UI por día tenían de promedio concentraciones 20,7 nmol/l más altas de 25(OH)D que sus homólogos no usuarios. Conclusiones: las características demográficas y un estilo de vida saludable son los principales factores asociados al uso de suplementos de vitamina D en los adultos mayores. Además, incluso entre los sujetos con densidad ósea baja, la suplementación con vitamina D entre 400 y 800 UI por día es adecuada para alcanzar los niveles óptimos de 25(OH)D.

The association between obesity and vitamin D status among older adults in Ecuador: analysis of the SABE survey.

BACKGROUND: although it is well established that body fat mass is inversely associated with vitamin D (25[OH]D) concentrations, little is known whether obesity increases the risk of 25(OH)D insufficiency among older adults in Ecuador. METHODS: the present study used data from the National Survey of Health, Wellbeing, and Aging to describe the prevalence of obesity and 25(OH) D insufficiency (< 20 ng/ml) among Ecuadorians aged 60 years and older. Logistic regression models were used to examine the independent association between obesity and 25(OH)D insufficiency. RESULTS: a total of 2,270 participants with a mean age of 71.5 (SD 8.1) years comprised the sample size, representing an estimated 1.1 million older adults in Ecuador. Overall, the crude prevalence of obesity was 19.2% and 25(OH)D insufficiency was present in 14.0% of men and 34.6% of women. Moreover, the proportion of women with 25(OH)D insufficiency remained steady across BMI categories. In contrast, 25(OH) D insufficiency prevalence rates in men increased progressively as body mass index (BMI) categories also increase. Moreover, obese older men (OR 2.04; 95% CI: 1.99-2.09) were two times more likely to have 25(OH)D insufficiency compared with those defined as having an ideal weight, even after adjustment for potential confounders. In women, this association was attenuated. However, 25(OH)D insufficiency prevalence ratesremained 12% higher in obese women (OR 1.12; 95% CI: 1.11-1.14) than their normal weight counterparts. CONCLUSION: obesity is associated with increased risk of 25(OH)D insufficiency in Ecuador. Thus, obese older adults should be offered vitamin D supplementation and counseled regarding lifestyle modifications to improved their 25(OH)D status.

Vitamin D Status among Older Adults Residing in the Littoral and Andes Mountains in Ecuador.

OBJECTIVES: To estimate the prevalence of 25-hydroxyvitamin D (25(OH)D) deficiency and its determinants among older adults in Ecuador. METHODS: 25(OH)D deficiency and insufficiency prevalence rates were examined among participants in the National Survey of Health, Wellbeing, and Aging. Logistic regression models were used to evaluate demographic characteristics associated with 25(OH)D deficiency. RESULTS: Of 2,374 participants with a mean age of 71.0 (8.3) years, 25(OH)D insufficiency and deficiency were present in 67.8% (95% CI, 65.3-70.2) and 21.6% (95% CI, 19.5-23.7) of older adults in Ecuador, respectively. Women (OR, 3.19; 95% CI, 3.15-3.22), self-reported race as Indigenous (OR, 2.75; 95% CI, 2.70-2.80), and residents in rural (OR, 4.49; 95% CI, 4.40-4.58) and urban (OR, 2.74; 95% CI, 2.69-2.80) areas of the Andes Mountains region were variables significantly associated with 25(OH)D deficiency among older adults. CONCLUSIONS: Despite abundant sunlight throughout the year in Ecuador, 25(OH)D deficiency was significantly prevalent among older women, Indigenous subjects, and subjects residing in the Andes Mountains region of the country. The present findings may assist public health authorities to implement policies of vitamin D supplementation among older adults at risk for this condition.

Determinants of osteoporosis prevention in low-income Mexican-American women.

BACKGROUND: Prevention is the most cost-effective means of managing osteoporosis. However, little is known about osteoporosis-related preventive practices in Mexican-American women. We examined factors that might influence women's decision to start preventive measures for osteoporosis. METHODS: Information was gathered through a cross-sectional survey of low-income Mexican-American women who were seen at two clinics in southern Texas. RESULTS: Of the 270 participants, 37% reported calcium supplementation, and 41% reported regular weight-bearing exercise to prevent osteoporosis. Fifty (41%) of the postmenopausal women were currently using hormone replacement therapy. Only 15% of the premenopausal and 13% of the postmenopausal women recalled that their health care provider had counseled them about prevention. Multivariate analysis showed that public education, bone densitometry evaluation, knowledge of osteoporosis, and counseling were determinants of prevention. CONCLUSION: Although osteoporosis is a preventable condition, our findings suggest that the majority of Mexican-American women do not receive adequate preventive measures or counseling about osteoporosis. Furthermore, we found that their health care provider's counseling about osteoporosis was a major determinant of osteoporosis prevention in these women.