About us and how we write
DozaVita is a reference guide to the vitamins and supplements sold on iHerb, written for readers in the UK and the EU. We explain which form to choose, how much to take and where the safe limits are.
Our expert: Alvina Klyuchko
nutritionist
Six years in sport, so she knows how nutrition and supplements hold up under real training loads. She reviews DozaVita articles – doses, forms, who should avoid what and interactions with medicines – against official guidance and clinical evidence.
What we do
We write about popular supplements and group them by goal: sleep, stress, immunity, energy and heart. Each guide shows how the forms differ and how much active ingredient a typical capsule contains. You’ll also find recommended intakes and upper limits, drug interactions and the cases when you should see a GP first.
Our English pages are written for the UK and the EU. We lead with NHS advice and EFSA limits, write in British English and give money figures in pounds and euros. US figures appear only as a second reference.
We don’t sell supplements and aren’t affiliated with manufacturers. The site earns money through the iHerb affiliate programme: if you buy through our link, we earn a commission and your price stays the same. The details are on our disclosure page.
Sources we rely on
- Official references: opinions from the European Food Safety Authority (EFSA), NHS guidance and fact sheets from the NIH Office of Dietary Supplements.
- Systematic reviews and meta-analyses of clinical trials, including Cochrane reviews.
- Clinical practice guidelines from professional bodies.
- Individual studies, only as supporting evidence and with their limitations noted.
We don’t treat customer reviews, manufacturer marketing or blogs as evidence, however many there are. Every article ends with its list of sources.
How much weight a source gets
Pick what a claim about a supplement rests on to see how we treat it
Source
How we use it
References for the numbers
Intakes, upper limits and safety data come from here. We check every dose in an article against the original source.
We take from it: intakes, limits, safety
How we use it
The main word on whether it works
A review or meta-analysis pools the clinical trials, Cochrane reviews included. That's what we use to judge whether a supplement does anything.
We take from it: effectiveness
How we use it
When you need a GP
Guidelines from professional bodies tell us when a blood test or a doctor comes first and when you can choose for yourself.
We take from it: tests, when to see a doctor
How we use it
Supporting evidence only
We mention an individual trial only alongside the reviews, and we always say where it falls short.
One study doesn't prove a supplement works.
How we use it
Not evidence
Customer reviews, manufacturer marketing and blogs never make our source list, however many of them there are.
How we write and check
- We check intake and limit figures against the original source.
- When the data is conflicting or thin, we say so.
- We don’t promise to “cure”, “boost immunity” or “burn fat”.
- We flag the groups a supplement isn’t right for: pregnancy, children, people with long-term conditions and people on medication.
Before an article goes out, our expert reviews it: Alvina Klyuchko, a nutritionist. She checks doses, forms, who should avoid a supplement and interactions with medicines. Reviewed pages carry her name at the top. New articles appear without it and get it once she has checked them.
How we prepare an article
Five steps from topic to publication. Tap a step
Choose the question
We pick questions people actually search for and check what evidence-based answers exist.
- Search query research
- We avoid topics that need a personal consultation
Gather the data
Intakes and limits come from NIH ODS and EFSA; effectiveness from systematic reviews.
- Reviews and ads don't count as evidence
- Every source is listed under the article
Write in plain language
We explain forms, doses and limits without promising cures.
- Who shouldn't take it
- What not to combine it with
Verify the numbers
Every dose and limit is checked against the original source. Then our nutritionist, Alvina Klyuchko, reviews the article, and reviewed pages carry her name.
- Checked against NIH ODS and EFSA
- Expert review
Keep it current
We review articles when guidance changes and at least once a year.
- Update date at the top of each article
- We fix errors readers report
What counts as evidence
Sources aren’t equal. A small study of a few dozen volunteers and a review pooling many trials are in different leagues, and the table shows which we trust more.
| Source | How we use it |
|---|---|
| EFSA, NHS, NIH ODS | intakes, upper limits, safety |
| Systematic reviews, Cochrane | effectiveness |
| Clinical guidelines | when you need a doctor or tests |
| Individual studies | supporting evidence only, with caveats |
| Reviews, ads, blogs | not used as evidence |
How the site is organised
- Supplements by goal group articles by what you want to sort out.
- The A–Z directory lists every nutrient we cover.
- Calculators help you check a dose, a cost per day or VAT on an order.
- The glossary explains terms such as elemental dose, NRV and upper limit.
Updates and corrections
We review articles when new official guidance comes out, and at least once a year. The update date sits at the top of each article. Spotted an error or an out-of-date figure? Email us and we’ll check and fix it.
Contact
Email: [email protected]
Updated