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Nutrient Bioavailability: How Your Body Absorbs Vitamins & Minerals
The master guide explaining why food charts lie without bioavailability: covering iron, calcium, B12, fat-soluble vitamins, and omega-3s.
By Nourish By Nutrients Editorial Team •
Updated: October 2026
Key Evidence Takeaways:
- Nutrient charts state what a food contains, not what your gastrointestinal tract can absorb and utilize.
- Heme iron absorbs at 15-35% while non-heme plant iron absorbs at 2-20% depending on Vitamin C co-factors.
- Fat-soluble vitamins (A, D, E, K) require 3-5g of co-consumed dietary fat for intestinal micelle absorption.