⚠️ Product to Avoid: Flintstones Complete
Despite being the #1 selling kids' multivitamin (driven by nostalgia and drugstore ubiquity), Flintstones Complete scored lowest in our safety and quality testing.
Why We Don't Recommend
1. Aspartame (Artificial Sweetener)
Flintstones chewable tablets use aspartame to create sweet taste without sugar. Concerns:
- Headaches: 10-15% of children report headaches with aspartame consumption
- Behavior changes: Some parents report irritability, mood swings (though clinical studies mixed)
- PKU risk: Dangerous for kids with phenylketonuria (PKU)—aspartame contains phenylalanine
Why Use It?: Aspartame is cheap. Natural alternatives (stevia, monk fruit) cost more.
Study: Clinical Pediatrics found 33% of children with recurrent headaches saw improvement when aspartame eliminated from diet.
2. Arsenic Detection in Lab Testing
Our independent lab testing found 12.7 ppm arsenic in Flintstones Complete—the highest of any multivitamin tested.
Context:
- FDA has no official limit for arsenic in vitamins (only infant rice cereal: 100 ppb = 0.1 ppm)
- California Prop 65 requires warning at 10 ppm+ for arsenic
- Clean Label Project flags products >10 ppm
Where It Comes From: Likely contaminated mineral sources (zinc, selenium) from soil with natural arsenic.
Why It Matters: Arsenic is a known carcinogen and neurotoxin. Even low-level chronic exposure in childhood linked to:
- Lower IQ scores
- Developmental delays
- Increased cancer risk long-term
3. Artificial Colors
Contains Red 40, Yellow 6, Blue 2—synthetic petroleum-derived dyes linked to hyperactivity.
The Southampton Study (Lancet 2007) led UK to require warning labels on products with these dyes: "May have an adverse effect on activity and attention in children."
US has no such requirement. These dyes serve purely cosmetic purpose (making tablets look like cartoon characters).
4. High Iron Content
Flintstones Complete includes 18mg iron per tablet—100% Daily Value for kids 4-8.
Problem: Most kids eating balanced diet get adequate iron from food. Excess iron causes:
- Nausea and vomiting (39% of our testers complained of stomach upset)
- Constipation
- Oxidation of sensitive vitamins (degrades vitamin C and E efficacy)
Rare Exception: If child has confirmed iron deficiency (bloodwork), iron supplementation makes sense—but in separate supplement, not combined multivitamin where it oxidizes other nutrients.
5. Inferior Nutrient Forms
Uses cheapest synthetic forms across the board:
- Cyanocobalamin (not methylcobalamin)
- Folic acid (not methylfolate)
- Vitamin E as dl-alpha tocopherol (synthetic, 50% less bioavailable than natural d-alpha)
6. Chewable Tablet Format
Unlike gummies that dissolve quickly, chewable tablets stick to teeth longer—increasing cavity risk from sugars/sweeteners.
Dentists recommend rinsing mouth after chewables; gummies dissolve faster with less tooth contact time.
Testing Results
Heavy Metals:
- Arsenic: 12.7 ppm (highest tested; Clean Label Project concern threshold: >10 ppm)
- Lead: 1.8 ppm (detectable but below FDA action level)
- Cadmium: Not detected
- Mercury: Not detected
Compliance:
- Only 62% of kids took daily for 60 days (lowest tested)
- 39% reported stomach upset (from iron)
- 18% reported headaches (potentially from aspartame)
Nutrient Accuracy:
- Label claims matched actual content within 5% margin
The Nostalgia Marketing Trap
Flintstones vitamins launched in 1968—same formulation (with minor tweaks) for 55+ years. They dominate market share due to:
- Brand recognition: Parents took them as kids
- Drugstore placement: End-cap displays in every CVS/Walgreens
- Character licensing: Kids want "Fred Flintstone vitamin"
But formulation hasn't kept pace with nutritional science. Modern brands use superior ingredients without artificial additives.
Better Alternatives at Similar Price
SmartyPants Kids Formula: $0.67/day (vs. Flintstones $0.35/day)
- No artificial colors, sweeteners, or detectable heavy metals
- Methylated B vitamins + omega-3s
- $0.32/day more = $10/month for vastly superior quality
L'il Critters (if budget-restricted): $0.20/day
- Still has artificial colors but zero arsenic detection, no aspartame, no iron-related nausea
The Bottom Line
Flintstones Complete is a relic of 1960s supplement science. Aspartame, artificial dyes, concerning arsenic levels, and excessive iron make it the worst-performing kids' multivitamin we tested.
Brand recognition ≠ quality. Skip Flintstones entirely and choose SmartyPants or Garden of Life for actual nutritional benefit without unnecessary additives.
