Dietary vitamin D intake is not associated with 25-hydroxyvitamin D3 or parathyroid hormone in elderly subjects, whereas the calcium-to-phosphate ratio affects parathyroid hormone

A Literature Review of the Potential Impact of Medication on Vitamin D Status

In recent years, there has been a significant increase in media coverage of the putative actions of vitamin D as well as the possible health benefits that supplementation might deliver. However, the potential effect that medications may have on the vitamin D status is rarely taken into consideration. This literature review was undertaken to assess the degree to which vitamin D status may be affected by medication. Electronic databases were searched to identify literature relating to this subject, and study characteristics and conclusions were scrutinized for evidence of potential associations. The following groups of drugs were identified in one or more studies to affect vitamin D status in some way: anti-epileptics, laxatives, metformin, loop diuretics, angiotensin-converting enzyme inhibitors, thiazide diuretics, statins, calcium channel blockers, antagonists of vitamin K, platelet aggregation inhibitors, digoxin, potassium-sparing diuretics, benzodiazepines, antidepressants, proton pump inhibitors, histamine H2-receptor antagonists, bile acid sequestrants, corticosteroids, antimicrobials, sulphonamides and urea derivatives, lipase inhibitors, hydroxychloroquine, highly active antiretroviral agents, and certain chemotherapeutic agents. Given that the quality of the data is heterogeneous, newer, more robustly designed studies are required to better define likely interactions between vitamin D and medications. This is especially so for cytochrome P450 3A4 enzyme (CYP3A4)-metabolized medications. Nevertheless, this review suggests that providers of health care ought to be alert to the potential of vitamin D depletions induced by medications, especially in elderly people exposed to multiple-drug therapy, and to provide supplementation if required.

Association between leisure-time aerobic physical activity and vitamin D concentrations among US older adults: the NHANES 2007-2012

BACKGROUND

Although previous studies have described a positive correlation between physical activity and 25-hydroxyvitamin D concentrations (25(OH)D), there have been inconsistent results in regard to the frequency or intensity of physical activity needed to achieve adequate 25(OH)D status.

AIMS

To examine the relationship between self-reported leisure-time physical activity and 25(OH)D₃ and 25(OHD) concentrations among US adults aged 60 years and older.

METHODS

The present analysis was based on data from participants in the National Health and Nutrition Examination Survey 2007-2012. Moderate or vigorous leisure-time physical activity was calculated by min/week or metabolic equivalent task scores-minutes/week and defined according to the 2008 Physical Activity Guidelines for Americans. General linear models adjusted for confounders were created to compare mean 25(OH)D and 25(OH)₃ concentrations across physical activity status.

RESULTS

A total of 4764 adults with a mean age of 69.7 years comprised the study sample. Overall, 33.3% men and 23.1% women were defined as physically active and participants' mean 25(OH)D and 25(OH)D₃ concentration was 75.0 and 68.8 nmol/L, respectively. Older adults physically active had 8.1 and 7.1 nmol/L higher 25(OH)D and 25(OH)₃ levels than those physically inactive, respectively. Moreover, higher 25(OH)D₃ and 25(OH)D concentrations were consistently seen during the summer and autumn months. In contrast, sedentary older adults had on average 25(OH)D levels < 75 nmol/L irrespective of the 6-month study period examined.

CONCLUSIONS

Leisure-time physical activity appears to be an effective manner of maintaining adequate vitamin D concentrations later in life. Therefore, promoting physical activity in older adults should be a national public health priority.

Vitamin D status among adults in Germany--results from the German Health Interview and Examination Survey for Adults (DEGS1)

Background

In 1998, more than half of the adult population in Germany had serum 25-hydroxy-vitamin-D [25(OH)D] levels below the common threshold of 50 nmol/l. Since then, there has been a lot of attention for vitamin D in the scientific community, the media and the general population and serum 25(OH)D levels may have increased as a consequence. With data from the ‘German Health Interview and Examination Survey for Adults’ (DEGS1) the current situation of vitamin D status can be analysed.

Methods

DEGS1, a national health survey among adults in Germany conducted by the Robert Koch Institute between 2008 and 2011, included 6,995 persons with available serum 25(OH)D levels. We calculated the proportion of participants with serum 25(OH)D levels <30 nmol/l, 30- < 50 nmol/l and > =50 nmol/l overall and according to age, season and latitude of residence as well as percentiles of serum 25(OH)D according to month of examination. Determinants of vitamin D status were analysed with multiple linear regression models.

Results

Mean serum 25(OH)D level was 45.6 nmol/l with no significant sex differences (p = 0.47). 61.6 % of the participants had serum 25(OH)D levels <50 nmol/l, 30.2 % had levels <30 nmol/l. During summer, half of the participants had levels > =50 nmol/l, during winter time, 25 % of the participants had levels <30 nmol/l. A significant latitudinal gradient was observed in autumn for men and in winter for women.

In multiple linear regression analyses, examination during winter time, residing in northern latitude, non-use of vitamin D supplements, low sport activity, high Body Mass Index (BMI) and high media consumption were independently and significantly associated with lower serum 25(OH)D levels in both sexes. In addition, among women, significant associations with lower 25(OH)D levels were observed for older age and lower socio-economic status, among men, for low vitamin D intake and more residential traffic.

Conclusions

Serum 25(OH)D levels below the threshold of 50 nmol/l are still common among adults in Germany, especially during winter and spring and in higher latitudes. Potentially modifiable factors of poorer vitamin D status are higher BMI, lack of sport activity and high media use.

Uptake of Dietary Sodium Restriction by Overweight and Obese Patients After Cardiac Revascularization

PURPOSE

High sodium intake increases the risk of cardiovascular diseases. Cardiac patients are recommended a daily sodium restriction of ≤1,500 mg. The purpose of this article is to describe daily sodium intake and sodium restriction adherence and its correlates in cardiac rehabilitation (CR) program participants following cardiac revascularizations.

DESIGN

This is a descriptive correlational study.

METHODS

A subanalysis was performed using the data collected from a randomized controlled trial to determine the effect of a 12-week weight management intervention.

FINDINGS

The average daily sodium intake was 3,020 mg ± 1,134 at baseline, 4,047 mg ±1,517 at 4 months, and 4,399 mg ± 1,722 at 6 months. The adherence rates were 4.8% at baseline and zero at 4 and 6 months. The factors influencing daily sodium intake were identified.

CONCLUSION

The CR program participants failed to adhere to the sodium restriction guidelines.

CLINICAL RELEVANCE

Rehabilitation nurses need to identify effective strategies to educate CR participants and their family members regarding dietary sodium adherence in CR participants.

Associations of serum 25-hydroxycholecalciferol and parathyroid hormone with serum lipids differ by sex and vitamin D status

Objective

Although emerging evidence indicates an association between vitamin D and serum lipids, the data are still inconsistent. The purpose of the present study was to investigate whether 25-hydroxycholecalciferol (25-hydroxyvitamin D3; 25(OH)D3) or intact parathyroid hormone (iPTH) was independently related to serum lipids in elderly women and men.

Design

Cross-sectional study. Fasting serum levels of 25(OH)D3, iPTH, TAG, total cholesterol (TC), HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) were assessed. Body composition was measured by bioelectrical impedance analysis. Lifestyle factors, such as nutrient intake, time spent outdoors, physical activity, smoking, supplement intake and medication, were assessed by questionnaires. Multiple regression analyses were performed to examine associations of 25(OH)D3and iPTH with serum lipids.

Setting

Giessen, Germany.

Subjects

One hundred and ninety-three well-functioning German elderly aged 66–96 years.

Results

After adjusting for age, body fat, physical activity, smoking, alcohol intake, lipid-modifying drugs and either iPTH or 25(OH)D3, 25(OH)D3was a predictor of TAG (standardised coefficient beta (β)=–0·180), HDL-C (β=0·197), LDL-C:HDL-C (β=−0·298) and TC:HDL-C (β=−0·302) in women, whereas iPTH was a predictor of HDL-C (β=−0·297) in men. In sub-analysis, associations between 25(OH)D3and TC (β=−0·252), HDL-C (β=0·230), LDL-C (β=−0·324), LDL-C:HDL-C (β=−0·412) and TC:HDL-C (β=−0·380) were found in women with 25(OH)D3concentrations above or equal the median vitamin D status (62·3 nmol/l), but not in women with lower 25(OH)D3concentrations.

Conclusions

In the elderly, associations of 25(OH)D3and iPTH with serum lipids may differ by sex and may require a vitamin D status above 62 nmol/l.