EAL

NSUP: Vitamin D (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To determine if ergocalciferol, in addition to calcium, reduces the risk of falls.

Inclusion Criteria:

Female
Between 70 and 90 years old
Community-dwelling
Serum 25-hydroxy Vitamin D concentration of less than 24.0ng per ml
History of falling within the last year.

Exclusion Criteria:

Current Vitamin D consuption
Current consumption of bone or mineral active agents apart from calcium
Bone mineral density Z-score at the total hip site of less than -2.0
Medical conditions or disorders that influence bone mineral metabolism, including renal insufficency
A fracture in the past six months
Mini-Mental State Examination score of less than 24
Presence of marked neurological conditions likely to substantially impair balance or physical activity, such as stroke or Parkinsons disease.

Description of Study Protocol:

Recruitment

Perth, Australia, area, by invitation letter sent to patients derived from three sources: Patients attending the emergency departments of teaching hospitals; patients receiving services from the local community home nursing service for management of falls; the electoral role that lists more than 98% of women in this age range.

Design

Randomized double-blind, placebo-controlled trial: 302 women aged 70 to 90 years, with a plasma 25OHD concentration of less than 24.0ng per ml, received either 1,000 IU per day of ergocalciferol supplement or placebo, along with 1,000mg calcium citrate tablets with their morning and evening meals for one year.

Blinding Used

Yes.

Intervention

Subjects were randomly assigned to consume either 1,000 IU per day of ergocalciferol supplement or placebo for one year, while consuming two 250-mg calcium citrate tablets with their morning and evening meals
Subjects were required to keep a diary of adverse events including falls.

Statistical Analysis

Multi-nomial logistic regression
Odds ratio
Relative ratio.

Data Collection Summary:

Timing of Measurements

The following data was collected at baseline:

Anthropometrics
Food frequency questionnaire
Mini-Mental State Examination
Demographic information.

The following data was collected at zero, six and 12 months:

Venous blood sample
Serum 25OHD concentration
Serum calcium
Serum phosphorus.

Description of Actual Data Sample:

Initial N

302 women

151 receiving ergocalciferol with calcium citrate
151 receiving placebo with calcium citrate.

Attrition

Described.

Age

Mean, receiving ergocalciferol with calcium citrate: 77±4.2 years
Mean, receiving placebo with calcium citrate: 77.4±5 years.

Ethnicity

Not described.

Anthropometrics

Mean weight, receiving ergocalciferol with calcium citrate: 73±13.9kg
Mean weight, receiving placebo with calcium citrate: 71.5±13.2kg.

Location

Perth, Australia.

Summary of Results:

Ergocalciferol therapy significantly reduced the risk of having one fall over one year between the two groups: Ergocalciferol Group, 53%; Control Group, 62.9% (OR, 0.61; 95% CI)

Subjects with ergocalciferol therapy significantly reduced the proportion of patients who had their first fall in winter or spring (OR, 0.55; 95% CI, 0.32-0.98)

Ergocalciferol therapy significantly reduced the risk of having one fall, but not multiple falls: Ergocalciferol Group, 21.2%; Control Group, 33.8% (OR 0.50; CI, 0.28-0.88).

Author Conclusion:

Patients with vitamin D insufficiency and a history of falling who live in sunny climates benefit from ergocalciferol supplementation in addition to calcium, which is associated with a 19% reduction in risk of falling, especially in winter
Ergocalcierol had no treatment benefit in summer, with levels of 23 OHD of 21.7ng per ml, however in the winter and spring, ergocalciferol resulted in a 23% reduction in the risk of falling and therefore, the authors propose that 25OHD levels averaging 27.1ng per ml should be considered adequate to prevent the risk of falling owing to vitamin D deficiency in elderly women living in the community.

Funding Source:

Government:

National Health and Medical Research Council, Australia

Reviewer Comments:

Females only
Randomization failed to correct for height (an important covariate)
Power calculation presented
Description of diet composition
Description of randomization scheme.

Quality Criteria Checklist: Primary Research
Relevance Questions
	1.	Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies)	Yes
	2.	Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about?	Yes
	3.	Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice?	Yes
	4.	Is the intervention or procedure feasible? (NA for some epidemiological studies)	Yes

Validity Questions
1.	Was the research question clearly stated?		Yes
	1.1.	Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified?	Yes
	1.2.	Was (were) the outcome(s) [dependent variable(s)] clearly indicated?	Yes
	1.3.	Were the target population and setting specified?	Yes
2.	Was the selection of study subjects/patients free from bias?		Yes
	2.1.	Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study?	Yes
	2.2.	Were criteria applied equally to all study groups?	Yes
	2.3.	Were health, demographics, and other characteristics of subjects described?	Yes
	2.4.	Were the subjects/patients a representative sample of the relevant population?	Yes
3.	Were study groups comparable?		Yes
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	Yes
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	Yes
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	Yes
	3.4.	If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis?	N/A
	3.5.	If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.)	N/A
	3.6.	If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")?	N/A
4.	Was method of handling withdrawals described?		Yes
	4.1.	Were follow-up methods described and the same for all groups?	Yes
	4.2.	Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	4.5.	If diagnostic test, was decision to perform reference test not dependent on results of test under study?	N/A
5.	Was blinding used to prevent introduction of bias?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	Yes
	5.2.	Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.)	Yes
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	N/A
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	N/A
	5.5.	In diagnostic study, were test results blinded to patient history and other test results?	N/A
6.	Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described?		Yes
	6.1.	In RCT or other intervention trial, were protocols described for all regimens studied?	Yes
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	Yes
	6.3.	Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect?	Yes
	6.4.	Was the amount of exposure and, if relevant, subject/patient compliance measured?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	N/A
	6.6.	Were extra or unplanned treatments described?	N/A
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	N/A
	6.8.	In diagnostic study, were details of test administration and replication sufficient?	N/A
7.	Were outcomes clearly defined and the measurements valid and reliable?		Yes
	7.1.	Were primary and secondary endpoints described and relevant to the question?	Yes
	7.2.	Were nutrition measures appropriate to question and outcomes of concern?	Yes
	7.3.	Was the period of follow-up long enough for important outcome(s) to occur?	Yes
	7.4.	Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures?	Yes
	7.5.	Was the measurement of effect at an appropriate level of precision?	Yes
	7.6.	Were other factors accounted for (measured) that could affect outcomes?	Yes
	7.7.	Were the measurements conducted consistently across groups?	Yes
8.	Was the statistical analysis appropriate for the study design and type of outcome indicators?		Yes
	8.1.	Were statistical analyses adequately described and the results reported appropriately?	Yes
	8.2.	Were correct statistical tests used and assumptions of test not violated?	Yes
	8.3.	Were statistics reported with levels of significance and/or confidence intervals?	Yes
	8.4.	Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	???
	8.6.	Was clinical significance as well as statistical significance reported?	Yes
	8.7.	If negative findings, was a power calculation reported to address type 2 error?	N/A
9.	Are conclusions supported by results with biases and limitations taken into consideration?		Yes
	9.1.	Is there a discussion of findings?	Yes
	9.2.	Are biases and study limitations identified and discussed?	Yes
10.	Is bias due to study's funding or sponsorship unlikely?		Yes
	10.1.	Were sources of funding and investigators' affiliations described?	Yes
	10.2.	Was the study free from apparent conflict of interest?	Yes