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Smoking status: not checked. Vitamin A: what these mean for you changes depending on whether you smoke or used to, and you have not told us. That check was skipped.
Head-to-head evidence comparison — which supplement is right for you?
Chlorella vs Vitamin A: Vitamin A has the stronger overall evidence (7 vs 6.5/10); they're alternatives for support immune system — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Vitamin A wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Too few graded studies
Top outcomes
Verdict
Limited support
2 of 9 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Chlorella and Vitamin A have evidence — compare verdict strength side-by-side.
3-10g daily
Before meals for detox, With food if GI sensitive, Away from medications (may bind)
Broken cell wall chlorella powder or tablets
The appropriate advice depends on the form of vitamin A, the reason for use, age, pregnancy status and total intake from all products. SupStack has not established a self-directed dose for this held use.
With fat-containing meal, Any time of day
Mixed carotenoids or low-dose retinyl palmitate
and 2 more not shown
4-8 weeks
4-8 weeks
8-12 weeks
First 1-2 weeks
2-4 weeks
2-4 weeks
4-8 weeks
With chronic excess
Identifying immunostimulatory herbal supplements that may flare autoimmune skin diseases: a systematic scoping review
Lupus science & medicine (2025) · Review
Scoping review screening 11,819 articles, of which 469 studies met inclusion criteria, identified 227 herbal supplements with immunostimulatory properties.
Effect of supplementation with Chlorella vulgaris on lipid profile in adults: A systematic review and dose-response meta-analysis of randomized controlled trials
Complementary therapies in medicine (2022) · Meta analysis · n=539
Meta-analysis of 10 RCTs with 539 adults (264 given Chlorella vulgaris, 275 controls).
Dietary Interventions in the Management of Fibromyalgia: A Systematic Review and Best-Evidence Synthesis
Nutrients (2020) · Systematic review
It is estimated to have a worldwide prevalence of 1.78%, with a predominance in females.
Effects of primary or secondary prevention with vitamin A supplementation on clinically important outcomes: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis
BMJ open (2024) · Meta analysis · n=1671672
Vitamin A did not reduce mortality in individually randomised trials (RR 0.99, 95% CI 0.93 to 1.05; I²=32%; p=0.19; 105 trials; moderate certainty), and this effect was not affected by the risk of bias.
Vitamin and Mineral Supplementation During Pregnancy on Maternal, Birth, Child Health and Development Outcomes in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis
Nutrients (2020) · Meta analysis · n=451723
IFA supplementation showed notable improvement in maternal anemia and the reduction in low birthweight, whereas LNS supplementation had no apparent effect on outcomes; further research that compares LNS and MMN supplementation could help understand differences with these commodities.
Vitamin A supplements for reducing mother-to-child HIV transmission
The Cochrane database of systematic reviews (2017) · Meta analysis · n=7298
Five trials in Malawi, South Africa, Tanzania and Zimbabwe, none of whose participants received antiretroviral therapy. Four trials had 6995 women and one had 303.
At 1.5 g a day for 8 weeks, a double-blind trial in 84 adults with type 2 diabetes found no change in blood lipids (PMID 33532874). At 5 g a day for 4 weeks, two double-blind trials found an effect: in 63 mildly hypercholesterolaemic adults total cholesterol changed -1.6% versus 0.03% on placebo (PMID 24920270), and in 34 adults eating three eggs a day LDL-C rose 1.7% versus 14.3% on placebo (PMID 27177615). At 15 g a day for 14 days, total and LDL cholesterol fell in 80 healthy adults (PMID 37049486), but uric acid rose and iron and selenium status fell. The meta-analyses disagree on dose: one found reductions at doses above 4 g a day (PMID 29037431), another found the LDL-C reduction at doses up to 1,500 mg and not above (PMID 35331862). No trial compared doses, so the curve is flat above 5 g and no minimum, optimal or safe ceiling is set.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin A has a higher evidence score (7/10 vs 6.5/10) and wins in 2 of 3 categories.
For support immune system, Vitamin A has a higher relevance score (75 vs 60).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.