Other ingredients: silicified Microcrystalline Cellulose, Stearic Acid, Hydroxypropyl Methylcellulose, Silica, modified Cellulose Gum, Magnesium Stearate
This score evaluates label quality — dosage disclosure, transparency, cleanliness of inactive ingredients, and formula composition. It does not measure clinical efficacy, bioavailability, or third-party testing. Read full methodology
Same category, higher SupplementScore. Based on dosage transparency, label cleanliness, and formula quality.
The research summaries below are about the ingredients in general, drawn from published studies that often use different doses, forms, and populations than this product. A "strong" evidence rating for an ingredient does not mean this product will produce that effect — studied doses may be significantly higher or lower than what is contained here. Always verify doses against the Supplement Facts table above.
Essential for rhodopsin production in the retina. Deficiency causes night blindness — one of the earliest recognized nutritional deficiencies.
Critical role in maintaining mucosal barriers and immune cell function.
Zinc is a cofactor for over 300 enzymes involved in immune cell development and function. Supplementation may reduce duration of common cold symptoms, particularly as lozenges. Essential for maintaining immune barrier integrity.
Essential for skin integrity and wound repair processes.
Primary structural component of bones. Adequate lifelong intake, combined with vitamin D, helps prevent osteoporosis — supported by extensive clinical evidence.
Essential for muscle contraction through calcium signaling.
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All scores are algorithmically generated from publicly available label data (NIH Dietary Supplement Label Database) and reflect label quality — not clinical efficacy, safety, or product quality. This page is not affiliated with or endorsed by Source Naturals. If you represent this brand and believe any information is inaccurate, please contact us for a correction. Read full methodology
Alternatives are selected from the same category (Vitamin C) with a higher overall score. This is not a recommendation — always verify ingredients and dosages match your needs.
May improve sleep quality, especially in older adults and those with low magnesium status.
60% of body magnesium is stored in bone. Essential for bone mineralization.
May reduce muscle cramps and support post-exercise recovery.
Adequate folate intake before and during early pregnancy reduces risk of neural tube defects. This is one of the most well-established findings in nutrition.
Essential cofactor for nucleotide synthesis and cell division.
Essential for red blood cell formation. Deficiency causes megaloblastic anemia, confirmed by decades of clinical evidence.
Involved in myelin synthesis and nerve function. Adequate B12 status supports neurological health, particularly in older adults and vegans.
Cofactor in energy production pathways, but supplementation only helps if deficient.
Supports immune cell function. Regular supplementation may modestly reduce cold duration, but does not prevent colds.
Potent water-soluble antioxidant that protects cells from oxidative damage.
Essential cofactor for enzymes involved in collagen production.
Protects polyunsaturated fatty acids in cell membranes from oxidation.
May help protect skin from UV damage when combined with vitamin C.
At 400mg/day (far above RDA of 1.3mg), riboflavin may reduce migraine frequency. Effect is dose-dependent and not expected at typical supplement doses.
Limited evidence. May help in cases of biotin deficiency but most people get adequate amounts from diet.
Essential cofactor for carboxylases involved in gluconeogenesis, fatty acid synthesis, and amino acid catabolism.
May support heart function and mitochondrial energy production. Some evidence for reducing statin-associated muscle discomfort.
Essential component of the electron transport chain in mitochondria.
Curcumin has anti-inflammatory properties in clinical studies, though bioavailability is low without enhanced formulations (piperine, liposomal, etc.).
Curcumin may reduce joint pain and inflammation in osteoarthritis. Effects depend on bioavailability — enhanced forms (BCM-95, Meriva, piperine) show better results than standard curcumin.
Multiple RCTs show cortisol reduction and improved stress/anxiety scores, primarily with standardized extracts (KSM-66, Sensoril) at 300-600mg/day.
Limited evidence for testosterone effects, primarily in stressed or subfertile men using KSM-66 extract. Results in healthy men are inconsistent.
May improve VO2 max, strength, and recovery. Typically studied at 300-600mg/day of standardized root extract (KSM-66 or equivalent).
Protects polyunsaturated fatty acids in cell membranes from oxidation.
May help protect skin from UV damage when combined with vitamin C.
Essential cofactor for pyruvate dehydrogenase and other enzymes in carbohydrate metabolism.
Essential for calcium absorption. Deficiency leads to rickets in children and osteomalacia in adults — a well-established causal relationship.
May reduce risk of respiratory infections. Active area of research.
Some association between low vitamin D levels and depression, but evidence is inconsistent.
Multiple RCTs show cortisol reduction and improved stress/anxiety scores, primarily with standardized extracts (KSM-66, Sensoril) at 300-600mg/day.
Limited evidence for testosterone effects, primarily in stressed or subfertile men using KSM-66 extract. Results in healthy men are inconsistent.
May improve VO2 max, strength, and recovery. Typically studied at 300-600mg/day of standardized root extract (KSM-66 or equivalent).
No FDA warnings or recalls on file.