Skip to content

Vitamin D 400iu

Fail

The top 5 products take 100% of clicks, so Vitamin D 400iu is a Fail.

Flapen Score
27
27 / 100
Ranks 2,022 of 2,035 Health & Personal Care niches · −21 vs the category median of 48
Market size
£39K/yr55K searches / yr
90-day growth
-49.0%search demand this quarter
Competition
100%top-5 click share · 4 brands · 16 sellers

Flapen Score

Vitamin D 400iu against its category

The dotted line is the Health & Personal Care average. Past it, Vitamin D 400iu is stronger. Inside it, weaker.

27Fail
Big MarketTrendingHigh ConversionOpen MarketLow ReturnsPrice rangeAvg priceNo Dominant BrandLow Review BarrierQuality Gap
This niche Category average

Market

The Vitamin D 400iu market on Amazon at a glance

Shoppers on Amazon United Kingdom searched for Vitamin D 400iu 55K times last year and spent an estimated £39K. All 4 brands take every click. Demand peaks in Jan–Feb–Oct–Nov. Flapen scores it 27 out of 100, a Fail.

01 · Demand

17.5% of searches ended in a purchase last week.

Shoppers searched for this 55K times in the last 12 months. That counts every search on Amazon United Kingdom for this niche's terms. In the latest week, 17.5% of those searches ended in a purchase. Searches in the last 90 days moved -49.0% against the 90 days before. Searches, conversion and average price together put the market at an estimated £39K a year.

Searches, last 12 months
55K
Growth, 90 days vs prior 90
-49.0%
Conversion, latest week
17.5%
Market size, estimated
£39Ka year
Peak month
November2.8× the quietest month
Top search term
vitamin d 400iu19K searches a year

02 · Price

A sale here is worth £4.03.

Listings sell for £4.03 on average, from £2.63 to £7.03. Amazon reports units sold in ranges. This niche sold 10K to 13K a year. The average listing sells 1,500 to 2,000 of them. At £4.03 that is £6K to £8K a year per listing.

Average price
£4.03under the $15 to $100 sweet spot
Price range
£2.63–£7.03
Amazon United Kingdom median price
£12.12across 27,606 niches
Units sold a year
10K–13K
Units per listing a year
1,500–2,000
Revenue per listing a year
£6K–£8K
Returns
0.0%of orders · Amazon United Kingdom median 0.6%

03 · Entry bar

The bar here is ads and reviews.

100% of listings pay for placement with sponsored ads. 100% ship with Prime. On an average day, 0.0% of listings are out of stock. The average listing ranks #41 within Vitamins. It carries 1,793 reviews at 4.60 stars, so a new listing needs social proof before a better product.

Sponsored listings
100%
Prime listings
100%
Out of stock, average day
0.0%
Average rank
#41in Vitamins
Average rating
4.60 starsAmazon United Kingdom average 4.36 stars
Average reviews
1,793per listing
Listings tracked
4

04 · Newcomers

Amazon counts 0 of last year's 1 launches as successful.

1 products launched here in the last 12 months. Amazon counts 0 of them as successful launches, new products that hit its first-year sales bar. The brands on the shelf have sold for 79 months on average, so the names here are established.

Launched, last 12 months
1
Successful launches
0Amazon's first-year sales bar
Average brand age
79 months

Products

Top Vitamin D 400iu products & what they sell for

Every tracked product: its share of the shelf, its reviews, and its price.

Competition

Competition: brands, sellers & click share

The top 5 products take 100% of clicks. A locked shelf that new listings rarely crack.

£0£6K£12K£17K£23K101001K10K Review Count Sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

Brands

4 falling

Sellers

16

Top-5 brand share

100%

Top 20: 100%

Top-5 click share

100%

Top 20: 100%

Open market

0%

  • Vitabiotics Ultra53%
  • Fultium23%
  • Natures Aid19%
  • PROHEALTH4%
  • Open — no brand owns it (0%)

Demand

Vitamin D 400iu search demand

Weekly searches over the year, seasonality beneath. Pick a range.

2K2KSpike '25Spike '26DecJanFebMarAprMayJunJulAugSepOctNovDecJanFebMarAprMayJun

Peak months: Jan, Feb, Oct, Nov · busiest ÷ quietest = 2.8×

Search terms

Top Vitamin D 400iu search terms shoppers use

The exact words shoppers type, with yearly volume, growth, and conversion.

  • vitamin d 400iu19K/yr
  • vitamin d3 400iu8K/yr
  • vitamin d 400 iu7K/yr
  • vitamin d 10 micrograms10K/yr
  • vitamin d 10mcg5K/yr
  • vitamin d 10mg4K/yr
  • vitamin d 4003K/yr

Reviews and returns

What reviews say buyers love and hate about Vitamin D 400iu

What buyers praise, what they complain about and why they send it back, from the reviews.

Complain

Size-Overall14%−0.02

The capsules are small

Slightly bigger tablets than I expected for this dose

Small in size

Dosage11%+0.25

Slightly bigger tablets than I expected for this dose

Its difficult to assess the beneficial impact of this supplement after only taking it for a few days

quite frankly you will overdose on them

Vitamin8%+0.18

Don't get nearly enough vit D via the sun

when i opened vitamins there was a green residue underneath lid

I had 400 tablet vitamins which were smaller than this thing

Functionality-Overall5%−0.08

96 doesn't work

Ease Of Chewing/Swallowing3%−0.04

I find tablets are always harder to swallow than capsules

Small to swallow

Love

Value For Money29%+2.79

Good Value

Good value for money

Worth it

Vitamin14%+0.18

Overall, this seems like a good basic vitamin D supplement

Vitamins, easy to swallow good amount of supply

This Vitamin D3 supplement is a great daily choice for supporting overall health

Ease Of Chewing/Swallowing13%−0.04

ideal to swallow

easy to ingest

Easy to swallow

Quality-Overall10%

Quality feels reliable and consistent, and the bottle has lasted well with regular use

Happy with the quality

Consistent product and trusted brand

Advertised Vs Actual Product6%+0.70

Does the job

Exactly what I wanted

Does what it says

FAQ

Common Vitamin D 400iu questions

Answered from the same tracked data.