Best Form of Vitamin C Calcium Threonate

Not all forms of Vitamin C Calcium Threonate are equal. The form determines how efficiently your body absorbs and uses the nutrient. Lower-quality forms — often found in mass-market supplements — can have dramatically lower bioavailability than premium alternatives.

FormulaForge ranks each form using a 100-point absorption score that combines peer-reviewed bioavailability percentage, formulary standing, relative multiplier versus the gold-standard form, and our bioavailability classification. Preferred forms represent the best available evidence for absorption efficiency.