How does DoseRank decide what ranks #1?

Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value. The #1 on the DoseRank tab has the highest composite; the other tabs re-rank the same products by Value, Trust, or Popularity. Placement is never paid.

Is a higher dose always better?

No. Dose-fit rewards landing inside the range studied for the outcome — over-dosing (common with melatonin) or under-dosing both lower the score. The goal is the effective dose, not the biggest number.

What does the Value score mean?

The Value score compares a product's price per serving with clinically relevant products ranked for the same outcome. A score of 50 is the typical price; above 50 means better value than typical, while below 50 means the product costs more than typical. It is a 0–100 value signal, not a percentile.

Why is the cheapest product not #1?

Cost is only one input. The cheapest pick here is a citrate form with weaker absorption and a stock-risk flag, so it leads on Value-for-cost but trails on the composite that also weighs evidence, dose fit and availability.

Are these affiliate links?

Retailer links may be affiliate links and DoseRank may earn a commission. Rankings and placement are determined by the scoring model only — never by payment from a brand.

Is this medical advice?

No. DoseRank summarizes evidence to help you choose; it is not a substitute for a clinician, especially if you are pregnant, breastfeeding, on medication, or managing a health condition.

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Reduce respiratory infections

DOSERANKEVIDENCE-BASED SUPPLEMENTS

Best Supplements for Respiratory infection incidence | DOSERANK

Top decision cards

Best products for respiratory infection incidence

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for respiratory infection incidence

Micro Ingredients, Vitamin D3 + K2, 300 Softgels

Micro Ingredients$0.10 / serving4.9 · 2,205Available now

Also helps with

Vitamin K status

Vitamin D status

Bone mineral density

Why this ranks here

Evidence fitVitamin D3 (Cholecalciferol) is the strongest evidence signal for this outcome.
Dose fitVitamin D3 (Cholecalciferol) at 5000 IU is higher than the studied 400-4000 IU window.
Price / serving$0.10 per serving — low price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

5000 IUAbove rangehigher than the studied 400-4000 IU window

100 mcg

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

ChildLife Essentials, Vitamin D3, Natural Berry, 12.5 mcg (500 IU), 1 fl oz (30 ml)

ChildLife EssentialsClinical87Dose fit67Popularity97$0.08/ serving

Natural Factors, Super Cod Liver Oil, 90 Softgels

Natural FactorsClinical89Dose fit54Popularity48$0.10/ serving

Paradise Herbs, Earth's Blend, Vitamin D3, 90 Vegetarian Capsules

Paradise HerbsClinical89Dose fit91Popularity48$0.12/ serving

Solaray, Vitamin D3 + K2, 60 VegCaps

SolarayClinical87Dose fit91Popularity97$0.28/ serving

Amazing Nutrition, Amazing Formulas, Calcium Magnesium Zinc + Vitamin D3, 300 Tablets

Amazing NutritionClinical87Dose fit68Popularity79$0.16/ serving

Paradise Herbs, Earth's Blend®, One Daily Superfood Multi-Vitamin, No Iron, 120 Vegetarian Capsules

Paradise HerbsClinical87Dose fit71Popularity88$0.25/ serving

Paradise Herbs, Earth's Blend, One Daily Superfood Multi-Vitamin with Iron, 120 Vegetarian Capsules

Paradise HerbsClinical87Dose fit71Popularity82$0.22/ serving

Codeage, Clearface Vitamins+, 90 Vegetable Capsules

CodeageClinical91Dose fit56Popularity48$0.60/ serving

KAL, Ultra D-3, Unflavored, 250 mcg (10,000 IU), 90 Micro Tablets

KALClinical89Dose fit94Popularity30$0.16/ serving

Top decision cards

Best products for respiratory infection incidence

Ranking by · Composite outcome score

Best overall — the composite outcome score.

Top pick · DoseRank

Why this ranks #1 for respiratory infection incidence

Micro Ingredients, Vitamin D3 + K2, 300 Softgels

Micro Ingredients$0.10 / serving4.9 · 2,205Available now

Also helps with

Vitamin K status

Vitamin D status

Bone mineral density

Why this ranks here

Evidence fitVitamin D3 (Cholecalciferol) is the strongest evidence signal for this outcome.
Dose fitVitamin D3 (Cholecalciferol) at 5000 IU is higher than the studied 400-4000 IU window.
Price / serving$0.10 per serving — low price tier for this outcome.
AvailabilityIn stock across major retailers; 99% availability confidence.
TrustStrong trust signals — consistently high marks from verified buyer ratings.

The numbers

5000 IUAbove rangehigher than the studied 400-4000 IU window

100 mcg

Compare top 3 Product data Open at retailer

The rest of the ranking · DoseRank

Top 10 ranked products

ChildLife Essentials, Vitamin D3, Natural Berry, 12.5 mcg (500 IU), 1 fl oz (30 ml)

ChildLife EssentialsClinical87Dose fit67Popularity97$0.08/ serving

Natural Factors, Super Cod Liver Oil, 90 Softgels

Natural FactorsClinical89Dose fit54Popularity48$0.10/ serving

Paradise Herbs, Earth's Blend, Vitamin D3, 90 Vegetarian Capsules

Paradise HerbsClinical89Dose fit91Popularity48$0.12/ serving

Solaray, Vitamin D3 + K2, 60 VegCaps

SolarayClinical87Dose fit91Popularity97$0.28/ serving

Amazing Nutrition, Amazing Formulas, Calcium Magnesium Zinc + Vitamin D3, 300 Tablets

Amazing NutritionClinical87Dose fit68Popularity79$0.16/ serving

Paradise Herbs, Earth's Blend®, One Daily Superfood Multi-Vitamin, No Iron, 120 Vegetarian Capsules

Paradise HerbsClinical87Dose fit71Popularity88$0.25/ serving

Paradise Herbs, Earth's Blend, One Daily Superfood Multi-Vitamin with Iron, 120 Vegetarian Capsules

Paradise HerbsClinical87Dose fit71Popularity82$0.22/ serving

Codeage, Clearface Vitamins+, 90 Vegetable Capsules

CodeageClinical91Dose fit56Popularity48$0.60/ serving

KAL, Ultra D-3, Unflavored, 250 mcg (10,000 IU), 90 Micro Tablets

KALClinical89Dose fit94Popularity30$0.16/ serving

Reduce respiratory infections

Reduce respiratory infections

Which ingredient types matter for respiratory infection incidenceOpen to see which ingredient types matter for respiratory infection incidence

Vitamins

Probiotics & Microorganisms

Fatty Acids & Lipids

Glandulars & Animal-Derived Extracts

Botanicals/Herbal Extracts

Antioxidants & Bioactive Compounds

Best products for respiratory infection incidence

Micro Ingredients, Vitamin D3 + K2, 300 Softgels

ChildLife Essentials, Vitamin D3, Natural Berry, 12.5 mcg (500 IU), 1 fl oz (30 ml)

Natural Factors, Super Cod Liver Oil, 90 Softgels

Paradise Herbs, Earth's Blend, Vitamin D3, 90 Vegetarian Capsules

Solaray, Vitamin D3 + K2, 60 VegCaps

Amazing Nutrition, Amazing Formulas, Calcium Magnesium Zinc + Vitamin D3, 300 Tablets

Paradise Herbs, Earth's Blend®, One Daily Superfood Multi-Vitamin, No Iron, 120 Vegetarian Capsules

Paradise Herbs, Earth's Blend, One Daily Superfood Multi-Vitamin with Iron, 120 Vegetarian Capsules

Codeage, Clearface Vitamins+, 90 Vegetable Capsules

KAL, Ultra D-3, Unflavored, 250 mcg (10,000 IU), 90 Micro Tablets

What every metric means

Compare the top 3, side by side

Not sure which is right for you?

Get a personal report

Frequently asked

Related outcomes

Which ingredient types matter for respiratory infection incidenceOpen to see which ingredient types matter for respiratory infection incidence

Vitamins

Probiotics & Microorganisms

Fatty Acids & Lipids

Glandulars & Animal-Derived Extracts

Botanicals/Herbal Extracts

Antioxidants & Bioactive Compounds

Related outcomes

Compare the top 3, side by side

Best products for respiratory infection incidence

Micro Ingredients, Vitamin D3 + K2, 300 Softgels

ChildLife Essentials, Vitamin D3, Natural Berry, 12.5 mcg (500 IU), 1 fl oz (30 ml)

Natural Factors, Super Cod Liver Oil, 90 Softgels

Paradise Herbs, Earth's Blend, Vitamin D3, 90 Vegetarian Capsules

Solaray, Vitamin D3 + K2, 60 VegCaps

Amazing Nutrition, Amazing Formulas, Calcium Magnesium Zinc + Vitamin D3, 300 Tablets

Paradise Herbs, Earth's Blend®, One Daily Superfood Multi-Vitamin, No Iron, 120 Vegetarian Capsules

Paradise Herbs, Earth's Blend, One Daily Superfood Multi-Vitamin with Iron, 120 Vegetarian Capsules

Codeage, Clearface Vitamins+, 90 Vegetable Capsules

KAL, Ultra D-3, Unflavored, 250 mcg (10,000 IU), 90 Micro Tablets