Bioavailability is how much of what you swallow actually reaches your body. It is often oversold with precise-sounding numbers that do not hold up. This tool skips the invented multipliers and gives what the evidence genuinely supports for each nutrient: what helps absorption, what hinders it, and where a popular claim is weaker than it seems. Pick a nutrient below.

How this works

This tool does not multiply your dose by a fixed number, because real absorption depends on the nutrient, the form, the meal, and the person, and single "x times better" figures are often taken from one small study. Instead it gives the direction the evidence supports: what tends to help, what tends to hinder, and where a common claim is shakier than the marketing suggests.

Understanding your result

Use the guidance as a way to get more from what you already take, mostly by pairing nutrients with the right foods and spacing them from the things that block them. The gains are real but usually modest, and they matter most for nutrients that are poorly absorbed to begin with, like non-heme iron and curcumin.

Important limitations

• Absorption varies by person, form, and meal, so treat this as general direction, not a precise figure.
• Some popular absorption claims come from single, small, or industry-funded studies and have not been reliably repeated.
• Enhancing absorption is not always wanted. For iron in particular, people with iron overload conditions should not try to boost it.
• This is general education, not personal advice.

Scientific basis

The absorption relationships here come from the NIH Office of Dietary Supplements:

• Iron fact sheet, NIH Office of Dietary Supplements
• Vitamin C fact sheet, NIH Office of Dietary Supplements

This calculator is for general education only and is not medical or professional advice. Always check product labels and speak with a qualified professional before making decisions about supplements.