EAL

FNOA: Aging Programs (2012)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

To identify associations of demographic, nutrition and health-related factors with vitamin D deficiency and vitamin D adequacy
To determine the effects of vitamin D—containing multivitamin supplements on vitamin D status and related biochemical measures in a subset of the population
To identify factors associated with non-response to vitamin D supplementation.

Inclusion Criteria:

Participants in the Older American Act Nutrition Programs in Georgia between 1998 and 2000.

Exclusion Criteria:

No exclusion criteria were described in the study.

Description of Study Protocol:

Recruitment

Study sites in Georgia were recruited by a letter sent to directors of each Older Americans Act Nutrition Program sites in Georgia. Participants at the study eight sites that agreed to take part in the study were recruited by site directors and employees who delivered meals to their homes or worked at senior centers.

Design

Cross-Sectional, Before-and-After Study

Blinding used

Not applicable

Intervention

Vitamin D supplementation was studied in some of the subjects, but due to high dropout rates, these findings cannot be considered in the evidence analysis.

Statistical Analysis

At baseline, the associations of sex and race with serum 25(OH)D, sunlight exposure, intake of vitamin D, calcium, and dairy foods and use of multivitamins was assessed by linear regression analysis for continuous variables and logistic regression analysis for categorical variables
At baseline, logistic regression analysis were used to evaluate the independent effects of age, gender, race, sunlight exposure, supplemental intake of vitamin D, and milk intake on vitamin D status
The influence of the multivitamin intervention was examined using paired t-tests and chi-square analysis to compare the pre and post-intervention variables
Non-responders and responders to the multivitamin intervention were compared using paired t-tests and chi-square analysis.

Data Collection Summary:

Timing of Measurements

Recruitment and testing took place between 1998 and 2000
Blood was collected from April through October and we obtained at baseline and after four months of supplement use
Questionnaires were administered by trained interviewers for information on eating patterns, sunlight exposure, general health, depression, cognition, medication use, use of vitamin-mineral supplements, and activities of daily living.

Dependent Variables

Vitamin D adequacy as measured by as measured by serum 25-hydroxyvitamin D. Deficiency was defined as serum 25(OH)D under 25nmol/l, insufficiency as 25 to <50nmol/l, and sufficiency as ≥50nmol/l.
Health status as measured by activities of daily living, medication use, anthropometric measurements, and questionnaires about general health
Depression was assessed using the Geriatric Depression Scale and body weight, height, calf-circumference, and triceps skinfold were measured.

Independent Variables

Demographic factors (age, race, gender)
Calcium intake as measured based on 24-hour recall using Food Processor software and Mini-Nutritional Assessment
Vitamin D intake as measured based on 24-hour recall using Food Processor software
Tobacco use as measured by self-reporting by participants
Sunlight exposure as measured by self-reporting by participants
Use of vitamin D supplements as measured by self-reporting by participants.

Control Variables

Description of Actual Data Sample:

Initial N:
- There were 158 subjects in the study
- 36 were taking multivitamin supplements at baseline
- 81% women and 19% men
Attrition (final N): Eight of the 36 supplement users identified at baseline were not used in the final analysis and were classified as "non-responders"
Age: Mean age was 77 years old
Ethnicity:
- 69% Caucasian
- 31% African American
Other relevant demographics:
- 124 participants (75%) received congregate meals
- 34 (22%) received home-delivered meals
Anthropometrics:
- BMI at baseline was 26.1 for those deficient in vitamin D
- 30.1 for those insufficient in vitamin D
- 28.1 for those were were adequate in vitamin D
Location: Georgia.

Summary of Results:

At baseline, 8.2% of participants were vitamin D deficient and 36.7% were vitamin D insufficient
African-Americans had lower mean serum vitamin D levels
Vitamin D deficiency was associated with receiving meals at home vs. at a congregate meal site, use of tobacco, low sunlight exposure, low intake of dairy foods, taking anti-anxiety medications, depression, dementia, and impairment in ADL's
Use of multivitamin supplements with calcium and vitamin D increased serum 25(OH)D by 56% and serum calcium by 4%
Vitamin D deficiency was associated with several markers of physical and mental disability, including low calf circumference, impaired activities of daily living, use of anti-anxiety medications, depression and dementia.

Association of Vitamin D Deficiency and Vitamin D Adequacy with Demographic, Nutrition, and Health-Related Variables at Baseline

	N	Vit D Deficient (<25nmol/l)	Vit D Insufficient (25 to <50nmol/l)	Vit D Adequate (≥50nmol/l)	P value <25 vs. ≥25	P value < 50 vs. ≥50
Age (years)	158	77±8	76±8	76±8	0.62	0.77
Men	30	10%	20%	70%	0.67	0.13
Women	128	8%	41%	52%
Caucasian	109	8%	26%	66%	0.98	0.0001
African American	49	8%	61%	31%
Education less than eight years	156	62%	48%	31%	0.11	0.08
Congregate meal	124	6%	42%	52%	0.05	0.75
Home delivered meal	34	18%	18%	65%
Using tobacco	154	38%	14%	15%	0.05	0.38
Serum calcium (nmol/l)	158	2.29±0.14	2.34±0.11	2.34±0.18	0.31	0.63
Serum alkaline phosphatase (U/L)	158	94.8±50.1	89.3±26.2	76.6±27.9	0.15	0.05
BMI (kg/m²)	153	26.1±6.9	30.1±7.5	28.1±6.0	0.20	0.69
Triceps skinfold (mm)	155	24±10	28±11	26±10	0.45	0.51
Calf circumference <31cm	155	34.6±5.8	35.9±5.2	35.9±3.7	0.35	0.99
Sun exposure less than one hour per week one to less than two hours per week at least two hours per week	88	100% 0% 0%	49% 28% 24%	27% 7% 67%
Taking Multi	157	15%	24%	45%	0.13	0.02
Vit D from supplements ≥10µg per day)	91	0%	5%	38%	0.30	0.01
Vit D from diet (µg per day) Men Women	91 16 75	4.7 1.6±1.3	6.8±5.6 2.3±1.8	5.7±7.1 2.7±2.0
Calcium from diet (µg per day) Men Women	91 16 75	940 418±175	1003±564 528±352	926±509 632±334
Milk, yogurt, cheese less than one serving per day at least one and less than two per day at least two per day	154	69% 15% 15%	44% 44% 12%	24% 43% 33%
Nutrition risk score (≥6/21)	154	69%	61%	40%	0.15	0.02
Number of prescription meds	154	3.2±2.2	3.5±2.1	3.8±3.3	0.58	0.77
Taking anti-anxiety meds	152	31%	5%	5%	0.01	0.12
Geriatric Depression Scale ≥11	98	56%	12%	23%	0.02	0.45
Having dementia	154	31%	5%	8%	0.02	0.37
Impaired Physical ADL (at least one)	101	30%	15%	23%	0.46	0.96
Impaired Instrumental ADL (at least one)	100	90%	35%	47%	0.02	0.95

P≤0.05 considered statistically significant

Intervention with Vitamin D-containing Multivitamin

	Pre-intervention	Post-intervention	P value
N	28	28
Months	April	August, September
Age	75±8
Men (percent)	11
Women (percent)	89
Caucasian (percent)	32
African American (percent)	68
Serum 25(OH)D nmol/	50.0±22.1	78.1±23.3	0.0001
Compliance not known (n=6)	47.1±11.1	73.8±24.7	0.78
Compliance <70% (n=8)	43±20.3	70.0±25.1
Compliance ≥79% (n=14)	55.2±26.1	84.7±21.4
<25nmol/l (percent)	4	0	0.0002
25 to <50nmol/l (percent)	57	14
50 to <75nmol/l(percent)	29	29
75 to <100nmol/l (percent)	4	36
≥100nmol/l (percent)	7	21
<50nmol/l (percent)	61	14	0.0003
≥50nmol/l (five)	39	86
Serum calcium (nmol/l)	2.32±0.14	2.42±0.14	0.0001
Serum alkaline phosphatase (U/L)	84.1±23.1	75.8±20.3	0.0002
Sun exposure (percent)
less than nine minutes per week	15	11	0.10
10-29 minutes per week	15	36
30-59 minutes per week	12	29
60-89 minutes per week	8	4
90-119 minutes per week	12	0
≥120 minutes per week	38	21
at least one hour per week	58	25	0.02

Other Findings

A vitamin D-containing multivitamin increased serum 25(OH)D by 56% after four months.

Author Conclusion:

Poor vitamin D status is common in older adults and may be particularly prevalent among older people enrolled in a community-based meal programs.

This study suggests that the reported patterns of sunlight exposure, milk consumption, and supplement use do not ensure that serum 25(OH)D exceeds 50nmol/l in this sample of the Older Americans Act Nutrition Program participants.

In conclusion, OAANP services did not prevent poor vitamin D and calcium status, but a supplement with vitamin D and calcium was beneficial.

Funding Source:

Government:	Centers for Disease Control and Prevention, Georgia Agricultural Experiment Station
Other:	Northeast Georgia Area on Aging

Reviewer Comments:

Much of the data collected was based on self-reported data, which is subject to reporting error.

It was reported that "36 older adults were recruited into the intervention with multivitamins" and were provided a multivitamin table, but in Table 1 in the article 157 of participants were reported as taking a multivitamin supplement. The reviewer is unclear on what the differences between the 36 and 157 are and how this might affect the results of the study.

Of the 36 that were recruited with multivitamins, eight were not used in the final analysis. The results of this portion of the study are not reliable due to 78% completion rate.

The sub-study of multi-vitamin users made it difficult for the reviewer to accurately complete the quality rating checklist because there were actually two different types of studies reported on in one paper, complicating the analysis of the paper and the studies.

The "n" in this study is small (158) and many variables were assessed. In this reviewer's opinion in many cases the numbers in various groups were too small to be meaningful.

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?		???
	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?	No
	2.2.	Were criteria applied equally to all study groups?	???
	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?	???
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	N/A
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	No
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	N/A
	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?	???
	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.)	???
	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%.)	???
	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?		???
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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.)	No
	5.3.	In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded?	No
	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?	N/A
	6.2.	In observational study, were interventions, study settings, and clinicians/provider described?	N/A
	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?	Yes
	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?	???
	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)?	N/A
	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