How AI Search Is Recommending Vitamins and Dietary Supplements: Monthly Trends

Executive Summary

September 2026 brought a mix of clear movement and notable stability to the Vitamins and Dietary Supplements category. Thorne retained its position as the coverage leader with valid recommendation coverage of 88.8%, down 2.0 points from 90.8% in August, while Nature Made held the second spot at 76.6%. The category's center of gravity remains at the top, with Thorne and Nature Made continuing to separate themselves from the rest of the tracked field.

The largest upward mover this month was Life Extension, which rose 5.4 points from 31.0% coverage in August to 36.4% in September — the largest gain of any tracked brand this month, and its first up month in the two-month series. The sharpest declines came from Ritual, down 6.6 points from 52.4% to 45.8%, and Garden of Life, down 6.0 points from 60.3% to 54.3% — the two largest declines in the category this period. These two declines, combined with Life Extension's rise, reshuffled the mid-tier of the category.

The most notable story of the month is the narrowing gap between Life Extension and Ritual. Life Extension trailed Ritual by 21.4 points in August, and that deficit has compressed to 9.4 points in September, a 12.0 point swing in a single month. This repositioning, alongside Nature Made's and Pure Encapsulations' steady performance, shows a competitive field where the middle tier is reordering even as category leadership stays unchanged.

Each monthly run begins with 800 prompt-surface observations (527 unique questions in August, 548 in September) across the benchmark's defined AI/search surface universe. Of those, 800 mentioned a tracked brand or competitor across both months; 800 were relevant and 0 were irrelevant in each month. The public metrics use the 754 observations (August) and 753 observations (September) that survive both qualification stages, spanning all six canonical AI surface families: ChatGPT, Copilot, Gemini, Perplexity, AI Overviews, and AI Mode.

Key Findings

Benchmark Context

The report separates the raw collection universe from the qualified analysis set. Brand-level recommendation percentages are calculated within the qualified benchmark set. Both months ran the same instrument with no break in methodology.

Benchmark-Level Metrics

The recommendation-shaped answer share and valid recommendation shortlist share both eased slightly from August to September, meaning AI systems produced slightly fewer directly comparable recommendation lists this month. The response mix shifted modestly toward ranked lists and factual answers, a compositional change worth watching in future months rather than a signal of category weakness.

AI Recommendation Trend

The category's top three brands hold steady while the middle tier reshuffles around two large declines and one strong rise.

None of the movement at the leadership level exceeded normal month-to-month variation; Thorne, Nature Made, and Pure Encapsulations all moved within a typical range. The category-level change came from two large declines in the mid-tier and one strong rise, plus a notable but smaller gain from NOW Foods, which together reordered positions from fourth through eighth.

What Changed This Month

Life Extension: the month's clearest upward mover

Life Extension's valid recommendation coverage rose 5.4 points from 31.0% in August to 36.4% in September — the largest gain of any tracked brand, and its first up month in the two-month series. This gain was driven in large part by broader presence: raw mention presence rose 4.9 points from 34.5% to 39.4%.

The brand's placement quality shows a more nuanced picture. While Life Extension's top-three rate improved 3.1 points from 10.3% to 13.4%, its rank-one rate slipped 0.1 points from 0.4% to 0.3%. In absolute terms, Life Extension appeared in valid recommendations 274 times in September versus 234 in August among the 753 qualified observations, but its rank-one count fell from 3 to 2.

The distinction to notice: Life Extension is being mentioned and recommended more often, but it is still rarely the first choice. The brand is broadening its base of recommendation appearances faster than it is converting those into top placements, which points to visibility growth ahead of preference growth.

Highest-priority diagnostic: Which prompt categories drove Life Extension's coverage gain, and in those prompts, which brands are still taking the rank-one position ahead of it?

Ritual: the month's largest coverage decline

Ritual's valid recommendation coverage fell 6.6 points from 52.4% in August to 45.8% in September, the largest single-brand movement in the category this month. The drop tracks closely with presence: raw mention presence fell 6.0 points from 55.6% to 49.5%.

Ritual's absolute counts tell the story of a broad retreat rather than a targeted loss. Valid recommendation appearances fell from 395 in August to 345 in September, and present counts fell from 419 to 373. Despite the coverage decline, Ritual's rank-one rate improved slightly from 2.4% to 2.8%, and its rank-one count rose from 18 to 21, suggesting the brand retained its strongest moments even as its overall footprint shrank.

The notable consequence is positional: Ritual's 12.0 point gap compression with Life Extension, and NOW Foods overtaking Ritual for the first time in the series (53.6% versus 45.8% in September, after trailing 48.8% to 52.4% in August). Ritual remains above the 45% line, but the brands immediately behind are closing ground.

Highest-priority diagnostic: Which AI surfaces or prompt types account for the 50-observation drop in Ritual's valid recommendation appearances between August and September?

Garden of Life: a second large decline

Garden of Life's coverage fell 6.0 points from 60.3% in August to 54.3% in September, dropping the brand from a clear fourth place into a tighter cluster. Its raw mention presence fell 5.6 points from 66.6% to 61.0%.

In absolute terms, Garden of Life's valid recommendation count dropped from 455 in August to 409 in September. Its quality signals were largely stable: top-three rate rose 1.7 points from 10.1% to 11.8%, rank-one rate fell a marginal 0.1 points, and sentiment remained flat at 1.0. The decline is therefore a presence story, not a preference story.

Garden of Life's 17.9 point lead over Life Extension (down from 29.3 points in August) shows how quickly a comfortable cushion can compress when one brand declines and another rises simultaneously. The brand is still in fourth, but its separation from the chasing pack has narrowed materially.

Highest-priority diagnostic: Which surfaces reduced Garden of Life's exposure, and did the decline concentrate in specific supplement categories where it previously held recommendation share?

NOW Foods: closing in on the top five

NOW Foods rose 4.8 points from 48.8% in August to 53.6% in September — just under the category's typical single-brand swing, but commercially meaningful nonetheless. The gain moves NOW Foods from sixth to fifth place, overtaking Ritual in the process. Raw mention presence rose 4.7 points from 54.1% to 58.8%, and rank-one rate improved from 0.1% to 0.9%, with rank-one count rising from 1 to 7.

NOW Foods' quality mix improved across the board: top-three rate rose 2.9 points from 10.1% to 13.0%, and net sentiment moved from 0.9 to 1.0. The brand's valid recommendation count rose from 368 to 404. This is the kind of broad-based gain that looks durable rather than the product of a single surface or prompt type.

Highest-priority diagnostic: Whether the rank-one gains concentrate in value-oriented prompts, which would position NOW Foods differently from premium-positioned brands in the same tier.

Buyer-Intent Interpretation

In September 2026, all 753 qualified observations fell into the Brand Recommendation cluster. No observations were captured for Pricing & Value or Multi-Brand Comparison, meaning the public benchmark cannot yet answer which brands win when shoppers explicitly weigh cost or ask for side-by-side comparisons. The current data reflects direct recommendation behavior only, which is the most common purchase-intent frame but leaves price sensitivity and comparative shopping unmeasured for this vertical.

Brand Opportunity Summary

The benchmark identifies where attention is warranted; a company-level analysis is needed to explain why specific brands gained or lost recommendation credit.

Evidence Behind the Benchmark

The aggregate metrics are built from prompt-level observations capturing the query, the AI surface, the recommendation outcome, the rank position, sentiment, and citations where exposed. Company-level analysis can go deeper into prompt, competitor, surface, and evidence patterns to explain the movements behind the percentages. Source presence is not automatically treated as proof of causation.

About This Benchmark

This report is part of the LLM Authority Index AI Market Discovery research program.

• AI Industry Market Discovery Methodology
• AI Industry Market Discovery Metrics
• AI Industry Market Discovery Standards

Report-Specific Interpretation Notes

• Small-count movements: brands with low valid recommendation counts, such as Nature's Bounty (49) and New Chapter (38), can show percentage swings from a handful of observations; interpret their movement with caution.
• Qualified denominator vs raw collection: the public metrics use the qualified observation set (753 in September) after funnel qualification, not the raw 800 prompt collection.
• Month-over-month analysis: movement identifies changes worth investigating; it does not by itself establish the cause of those changes.

Next Step

The Public Benchmark Shows Where a Brand Is Winning or Losing. A Company-Level Audit Shows Why.

Beneath the aggregate percentages sit the questions that matter for strategy: which high-intent prompts is a brand winning, which competitor takes the recommendation when a brand loses, what attributes does the AI associate with each option, and which external sources shape those answers. A brand that understands these patterns can act with precision rather than guessing from summary statistics.

A company-specific AI visibility audit maps those prompt, surface, competitor, ranking, sentiment, and evidence-source patterns into a prioritized visibility strategy, showing exactly where to focus content, authority, and citation-building efforts.

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