| Ingredient | Amount | % DV% Daily Value — how much of the recommended daily intake one serving provides, based on a 2,000 calorie diet. 100% = full daily need. Values over 100% are common for water-soluble vitamins (B, C) and generally safe. Values over 200% are highlighted. |
|---|---|---|
| Vitamin D | 4000 IU | 1000% |
| Thiamine | 15 mg | 1000% |
| Riboflavin | 17 mg | 1000% |
| Niacin | 10 mg | 50% |
| Vitamin B6 | 10 mg | 500% |
| Folate | 400 mcg | 100% |
| Vitamin B12 | 120 mcg | 2000% |
| Pantothenic Acid | 10 mg | 100% |
| Iodine | 150 mcg | 100% |
| Magnesium | 80 mg | 20% |
| Zinc | 22.5 mg | 150% |
| Selenium | 140 mcg | 200% |
| Manganese | 1 mg | 50% |
| Copper | 0.5 mg | 25% |
| Chromium | 120 mcg | 100% |
| Spark Thyroid Complex | 604 mg | — |
Other ingredients: Cellulose, Rice Extract
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.
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.
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.
No reviews yet.
Alternatives are selected from the same category (Vitamin D) with a higher overall score. This is not a recommendation — always verify ingredients and dosages match your needs.
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.
Involved in neurotransmitter synthesis including serotonin and dopamine. Cofactor for over 100 enzyme reactions.
B6 is a cofactor in the transsulfuration pathway, converting homocysteine to cysteine. This is a separate pathway from the B12/folate remethylation route.
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.
At pharmacological doses (1500-3000mg), niacin may improve HDL cholesterol. This effect is dose-dependent and not expected at typical supplement doses.
Essential coenzyme (NAD/NADP) in hundreds of metabolic reactions.
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.
Essential cofactor for pyruvate dehydrogenase and other enzymes in carbohydrate metabolism.