vitamin d 400 iu
Skip itA deep review moat (16,363 avg reviews) — this niche doesn't clear our bar today.
Returns
Incredible0.0%return rate — above 5% kills the launch gate
Conversion
Great11.4%search→purchase rate — share of searches ending in a sale
Brand share
Good70%top-5 brand share — brands hold most of the demand
Avg price
Okay$11.42avg listing price — sweet spot $15–$100
Competition
Okay60%top-5 click share — leaders hold, buyers still browse
Growth
Okay+3.8%90-day search growth — must beat 0% to launch
Market size
Okay$121K$121K/yr · 93K searches
Price range
Okay$4.86–$18.97cheapest to priciest tracked listing — scored on the share inside $15–$100
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Review moat
Bad16,362.77avg incumbent reviews — the moat a new listing must climb
According to Flapen's Amazon United States niche tracking, vitamin d 400 iu is a $121K/yr Amazon United States market (93K searches/yr). The top 5 brands hold 70% of demand. Demand peaks in May–Jul. Verdict: Skip it — 46/100.
Data updated Aug 5, 2026 · scored weekly · How we score niches
vitamin d 400 iu market data
- Units sold / yr
- 13K–15K
- avg 750–1,000/product
- Revenue / yr
- $143K–$171K
- units × avg price
- Conversion rate
- 11.4%
- Avg BSR
- #609
- Page quality
- 0%
- Prime
- 91%
- Sponsored
- 68%
- Out of stock
- 0.0%
- Avg brand age
- 101 months
- Avg seller age
- 154 days
Competition & brand share
The top 5 products take 60% of clicks — established leaders, but buyers still shop beyond them.Brands
16 rising
Sellers
111
Top-5 brand share
70%
Top 20: 100%
Top-5 click share
60%
Top 20: 98%
Open market
24%
- Nature's Truth26%
- NOW Foods17%
- Carlyle11%
- Swanson8%
- Pure Encapsulations7%
- Nature Made7%
Demand & seasonality
Weekly Amazon search volume, last 101 weeks — +3.8% search growth over the last 90 days.Peak months: May, Jul · busiest ÷ quietest = 1.7×
Top vitamin d 400 iu search terms
- vitamin d 400 iu18K/yr
- vitamin d3 400 iu16K/yr
- vitamin d3 400iu8K/yr
- vitamin d 500 iu9K/yr
- vitamin d3 500 iu5K/yr
- vitamin d 5005K/yr
- low dose vitamin d5K/yr
- d3 400 iu4K/yr
- vitamin d 4003K/yr
- natures truth d33K/yr
Top vitamin d 400 iu products on Amazon
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 22 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Natures Truth Vitamin D3 400 IU 100 Count
Nature's Truth$6.854.7★1,046 rev
NOW Supplements Vitamin D-3 400 IU Strong Bones* Structural support* 180 Softgels
NOW Foods$4.864.7★5,350 rev
Carlyle Vitamin D3 400iu (10mcg) | 400 Tablets | Value Size
Carlyle$9.194.7★374 rev
Pure Encapsulations Vitamin D3 10 mcg (400 IU) | Hypoallergenic Support for Bone Breast Cardiovascular Colon and Immune Health* | 120 Capsules
Pure Encapsulations$18.014.6★306 rev
Swanson Vitamin D3 Bone Health 400 IU (10 mcg) 250 Capsules
Swanson$7.444.4★56 rev
Newest
by launch date
Bronson Vitamin D3 1000 IU (25mcg) Low Dose Vitamin D 360 Tablets
Bronson$9.8593 rev
Vitamin D3 10 mcg (400 IU) 200 Softgels - Dietary Supplement (Pack of 1)
Unique Bundle Store$15.0150 rev
Natures Truth Vitamin D3 5000 IU Softgels | 400 Count | High Potency | Non-GMO & Gluten Free Supplement
Nature's Truth$18.97325 rev
Natures Truth Vitamin D3 Gummies | 5000 IU | 60 Count | Peach Flavor | Vegetarian Non-GMO & Gluten Free Supplement
Nature's Truth$9.89795 rev
Carlyle Vitamin D3 400iu (10mcg) | 400 Tablets | Value Size
Carlyle$9.19374 rev
Trending
90-day click momentumBronson Vitamin D3 1000 IU (25mcg) Low Dose Vitamin D 360 Tablets
Bronson$9.854.7★
Swanson Vitamin D3 Bone Health 400 IU (10 mcg) 250 Capsules
Swanson$7.444.4★
NOW Foods Vitamin D-3 400 IU Softgels 2 pk 180 Count (Pack of 2)
NOW Foods$11.034.7★
Nature Made Vitamin D3 1000 IU (25 mcg) 180 Vitamin D Softgels
Nature Made$8.674.8★
Natural Nutra Vitamin D3 400 IU Softgels Gluten-Free Vitamin D 100 Count
Natural Nutra$15.054.6★
What buyers say about vitamin d 400 iu
What buyers praise and complain about, mined from review topics.What buyers love
“Quality vitamins”
“the quality seems consistent”
“fair price”
“Easy peasy”
“accurately described”
“Tastes great and is easy to chew”
“The dropper makes dosing straightforward”
“very effective”
“It doesnt seem to change the taste of the milk so she drinks it just fine”
“I like the usda organic certification”
What buyers complain about
“leaking issue”
“Very small bottle size”
“Its a very low dose”
“Not normal vitamin smell, more rancid”
“Doesn't taste like anything”
“Cant provide results yet”
“Bottle is different from the box”
“Not high quality”
“Doesnt smell like anything”
“Not an easy disoenser”
Top return reasons
Common questions
- Is vitamin d 400 iu profitable to sell on Amazon United States?
- The niche generates $121K/yr across 22 tracked products. 1 of 1 products launched in the last 360 days are still selling. 90-day search growth is +3.8%. Flapen's verdict: Skip it (46/100).
- How competitive is the vitamin d 400 iu niche?
- 16 brands and 111 sellers compete. The top 5 products take 60% of clicks and top 5 brands hold 70% of demand.
- What do buyers complain about in vitamin d 400 iu?
- Top complaints mined from reviews: Leak-Proof, Size-Overall, Dosage. The return rate is 0.0%.
- When does demand for vitamin d 400 iu peak?
- Demand peaks in May–Jul; the busiest month runs 1.7× the quietest.
- What does it cost to enter the vitamin d 400 iu niche?
- Listings span $4.86–$18.97; the average listing price is $11.42 (sweet spot $15–$100). The average incumbent carries 16,363 reviews — the moat a new listing must climb.