The Study
Vitamin D, leptin and impact on immune response to seasonal influenza A/H1N1 vaccine in older persons
This study looked at whether people with more vitamin D had a better immune response to the flu shot, but it didn’t make anyone take vitamin D — it just noticed what was already there. So it can say 'people with more vitamin D sometimes had a tiny bit stronger immune signal,' but it can’t say vitamin D made the immune system better.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Scientists checked if people with more vitamin D in their blood had a stronger immune reaction to the flu vaccine.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 543 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The granzyme-B link is very weak and likely not meaningful for most people.
- 2The gene links are statistical and don't prove vitamin D causes better immunity.
- 3Vitamin D levels didn't affect antibody levels after the shot.
- 4But people with higher vitamin D had a tiny bit more granzyme-B (a immune protein) after 75 days.
- 5Three gene versions were linked to higher vitamin D levels.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Human Vaccines & Immunotherapeutics
Year
2016
Authors
S. Sadarangani, I. Ovsyannikova, Krista M. Goergen, D. Grill, G. Poland
Related Content
Claims (3)
People aged 50 to 74 who have a little more vitamin D in their blood before getting the flu shot tend to have a slightly stronger immune cell response to the vaccine a few weeks later — but the connection is very small.
People aged 50 to 74 who have high or low levels of vitamin D in their blood before getting the flu shot tend to have about the same level of antibody response after the shot—vitamin D doesn’t seem to make a difference.
Scientists found that three tiny differences in a person’s DNA, all in the same gene, are linked to how much vitamin D they naturally have in their body when they’re healthy and between 50 and 74 years old.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.