Vitamin D 400iu
FailThe top 5 products take 100% of clicks, so Vitamin D 400iu is a Fail.
- Flapen Score
- 27 / 100Ranks 2,022 of 2,035 Health & Personal Care niches · −21 vs the category median of 4827
- 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.
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
An estimated 17.5% of those searches ended in a purchase.
Shoppers searched for this 55K times in the last 12 months. That counts every search on Amazon United Kingdom for this niche's terms. An estimated 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
0 of last year's 1 launches cleared the first-year sales bar.
1 products launched here in the last 12 months. 0 of them cleared the first-year sales bar, our mark for a successful launch. 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
The products selling here, as shoppers see them on Amazon. Shelf share and sales are our estimates.
Prices and ratings read from Amazon on Jul 25, 2026. The live listing can differ.
Top sellers
by estimated 90-day click share
Vitamin D Tablets 400IU Vitabiotics Ultra
- Price
- £2.63
- Rating
- 4.7/5
- Reviews
- 1,658
- Age
- 2y ago

Fultium Vitamin D3 400 IU 10g |90 Tablets|Recommended Daily Dose Vitamin D Supplement | Immune Bone & Muscle Support | from The UKs No.1 Vitamin D Prescription Brand | Vegetarian | Food Supplement
- Price
- £2.80
- Rating
- 4.6/5
- Reviews
- 58
- Age
- 5mo ago

Natures Aid Vitamin D3 10g (400IU) High Strength Vitamin D Supplement Supports Bones Muscles & Immunity Vegan Gluten-Free Non-GMO 90 Tablets Essential Daily Nutrient
- Price
- £3.65
- Rating
- 4.6/5
- Reviews
- 5,083
- Age
- 17y ago

Certified Vegan 400IU Vitamin D3 120 Days Tablets for Pregnancy Nursing and Seniors - NHS Approved
- Price
- £7.03
- Rating
- 4.5/5
- Reviews
- 374
- Age
- 4y ago
Trending
estimated 90-day click momentum
Fultium Vitamin D3 400 IU 10g |90 Tablets|Recommended Daily Dose Vitamin D Supplement | Immune Bone & Muscle Support | from The UKs No.1 Vitamin D Prescription Brand | Vegetarian | Food Supplement
- Price
- £2.80
- Rating
- 4.6/5
- Reviews
- 58
- Age
- 5mo ago

Vitamin D Tablets 400IU Vitabiotics Ultra
- Price
- £2.63
- Rating
- 4.7/5
- Reviews
- 1,658
- Age
- 2y ago

Natures Aid Vitamin D3 10g (400IU) High Strength Vitamin D Supplement Supports Bones Muscles & Immunity Vegan Gluten-Free Non-GMO 90 Tablets Essential Daily Nutrient
- Price
- £3.65
- Rating
- 4.6/5
- Reviews
- 5,083
- Age
- 17y ago

Certified Vegan 400IU Vitamin D3 120 Days Tablets for Pregnancy Nursing and Seniors - NHS Approved
- Price
- £7.03
- Rating
- 4.5/5
- Reviews
- 374
- Age
- 4y ago
Newest
by launch date
Fultium Vitamin D3 400 IU 10g |90 Tablets|Recommended Daily Dose Vitamin D Supplement | Immune Bone & Muscle Support | from The UKs No.1 Vitamin D Prescription Brand | Vegetarian | Food Supplement
- Price
- £2.80
- Rating
- 4.6/5
- Reviews
- 58
- Age
- 5mo ago

Vitamin D Tablets 400IU Vitabiotics Ultra
- Price
- £2.63
- Rating
- 4.7/5
- Reviews
- 1,658
- Age
- 2y ago

Certified Vegan 400IU Vitamin D3 120 Days Tablets for Pregnancy Nursing and Seniors - NHS Approved
- Price
- £7.03
- Rating
- 4.5/5
- Reviews
- 374
- Age
- 4y ago

Natures Aid Vitamin D3 10g (400IU) High Strength Vitamin D Supplement Supports Bones Muscles & Immunity Vegan Gluten-Free Non-GMO 90 Tablets Essential Daily Nutrient
- Price
- £3.65
- Rating
- 4.6/5
- Reviews
- 5,083
- Age
- 17y ago
Competition
Competition: brands, sellers & click share
The top 5 products take an estimated 100% of clicks. A locked shelf that new listings rarely crack.
Brands
4 falling
Sellers
16
Est. top-5 brand share
100%
Top 20: 100%
Est. 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.
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 estimated 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
We read the reviews and the return reasons for every product selling here.
“The capsules are small”
Every topic
Every topic buyers talk about, one row each.
Red shows the share of negative reviews and green the share of positive reviews, biggest topic first. Open a row to read what they wrote.
15 topics
Keep looking
Related niches
Niches in the same category that score near this one. Research these next.
Best Flapen score
The highest-scoring niches we track right now, across every category.
FAQ
Common Vitamin D 400iu questions
Answered from the same tracked data.
Figures on this page are estimates modeled from public Amazon pages and third-party keyword data. Amazon does not supply them, and no connected seller's data is used. How we handle Amazon data









