Vitamin D3, 25 mcg (1000 IU) Review

Zahler Vitamin D3, 25 mcg (1000 IU) received a product quality score of 100/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 1 active ingredients with 120 servings per container. All 4 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Zahler, holds a brand trust score of 81/100.

Zahler Vitamin D3, 25 mcg (1000 IU) contains 1 active ingredients: Vitamin D3 (Cholecalciferol) (1,000 IU) (25 mcg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

GoodSupp reviewed the inactive-ingredient data available for Zahler Vitamin D3, 25 mcg (1000 IU). All 4 inactive ingredients — including capsule materials, fillers, and binders — are currently classified as safe in GoodSupp's ingredient reference data. This label analysis cannot determine whether the product is safe for a particular person, and source labels may change. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Zahler receives a brand trust score of 81/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 2005 and headquartered in Brooklyn, NY, USA, the company offers 174 products in their lineup. Note: Zahler has 4 historical regulatory incidents on record, which are factored into the trust score.

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.

This is an important question for supplement consumers. The dietary supplement industry is largely self-regulated, which means product quality, ingredient transparency, and safety practices vary significantly between brands and products. The most reliable way to evaluate any supplement is to check for third-party testing certifications, review the full ingredient list and dosages, and research the brand's regulatory track record. GoodSupp's database of over 150,000 analyzed products provides independent quality scores, ingredient safety ratings, and brand trust reports to help you make evidence-based decisions.

The optimal dosage depends on your individual health needs, age, sex, and current nutrient levels. Recommended daily amounts are established by health authorities but may vary from therapeutic doses used in clinical research. It's important to check the Supplement Facts label for the exact amount per serving and compare it against the % Daily Value. Some supplements provide mega-doses well above the Daily Value, which may not be necessary and in some cases could be harmful — particularly for fat-soluble vitamins (A, D, E, K) that accumulate in the body. GoodSupp's efficacy analysis evaluates whether a product's dosages align with clinically studied amounts. Always consult your healthcare provider for personalized dosage recommendations.