What is the approximate amount of zinc absorbed from a 60 mg dose of zinc glycinate, taken as 30 mg every 12 hours?

Zinc Absorption from 60 mg Zinc Glycinate (30 mg twice daily)

You absorbed approximately 18-22 mg of elemental zinc from your 60 mg total daily dose of zinc glycinate, taken as 30 mg every 12 hours.

Absorption Efficiency Based on Dose and Formulation

Your dosing strategy of splitting 60 mg into two 30 mg doses every 12 hours is physiologically sound and maximizes absorption efficiency compared to taking the full dose at once. Here's why:

Dose-Response Relationship

• At 30 mg per dose, you absorb approximately 11-12 mg per dose, based on research showing that zinc absorption follows a saturable dose-response curve where maximum absorption plateaus around 13 mg at doses above 20 mg 1
• Taking two 30 mg doses separated by 12 hours yields approximately 22-24 mg total absorbed zinc per day (11-12 mg × 2 doses), which is substantially more efficient than taking 60 mg as a single dose 1
• The fractional absorption percentage decreases as dose increases: at 20 mg you absorb approximately 54%, at 30 mg approximately 37%, but the absolute amount absorbed plateaus around 11-13 mg per dose 1

Formulation Advantage

• Zinc glycinate is an organic compound with superior tolerability and comparable absorption efficiency to other organic forms like zinc gluconate, zinc histidinate, and zinc orotate 2, 3
• Organic zinc compounds demonstrate better tolerability than inorganic salts (zinc sulfate, zinc chloride) while maintaining similar efficacy 2, 3
• When taken without food, organic zinc forms like glycinate achieve fractional absorption rates of 50-70% at lower doses (under 15 mg), but this percentage decreases at higher doses even though absolute absorption continues to increase 1, 4

Timing and Absorption Optimization

Your Current Regimen

• Splitting doses every 12 hours prevents complete saturation of intestinal zinc transporters (ZIP4, ZnT1), allowing each dose to be absorbed more efficiently than a single large dose 3, 5
• The American Association for the Study of Liver Diseases recommends taking zinc at least twice daily when total daily doses reach 75 mg or higher, and your 60 mg dose benefits from this same principle 3

Food Timing Considerations

• Taking zinc 30 minutes before meals optimizes absorption, as food significantly interferes with zinc uptake 3, 6
• If you're taking your zinc glycinate with food, your actual absorption may be reduced by 20-40%, bringing your total absorbed zinc down to approximately 13-18 mg per day rather than 22-24 mg 3
• However, if gastrointestinal tolerance is problematic, taking zinc with food is acceptable with the understanding that absorption is modestly reduced 3, 6

Clinical Context and Safety

Adequacy of Absorption

• Your absorbed amount of 18-22 mg per day exceeds the population reference intake of 16.3 mg/day for men and 12.7 mg/day for women 7
• This level is appropriate for therapeutic supplementation in documented deficiency states or conditions with increased zinc losses 2
• The ESPEN guidelines recommend 0.5-1 mg/kg per day of elemental zinc for acquired zinc deficiency, which for a 70 kg adult would be 35-70 mg daily, suggesting your regimen falls within therapeutic ranges 2

Important Caveats

• Zinc absorption is determined by current intake, not zinc status - your body doesn't upregulate absorption based on deficiency but rather adjusts endogenous losses to maintain homeostasis 5
• Monitor copper status when taking 60 mg zinc daily, as this dose requires maintaining an 8:1 to 15:1 zinc-to-copper ratio (meaning 4-7.5 mg copper daily) to prevent zinc-induced copper deficiency 6, 7
• Consider taking copper supplementation at a different time of day (separated by several hours) to minimize direct competition at the intestinal level 6
• Zinc toxicity symptoms appear at intakes exceeding 1-2 grams, but chronic intake above 50 mg can interfere with copper absorption even without acute toxicity 2, 7

Monitoring Recommendations

• Plasma zinc should be measured with simultaneous CRP and albumin to confirm adequacy of supplementation and rule out deficiency 2
• If supplementing long-term at 60 mg daily, recheck zinc and copper levels after 3 months 6
• Watch for signs of copper deficiency including anemia, leukopenia, thrombocytopenia, and neuromuscular abnormalities if supplementing zinc without adequate copper 6