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    Ingredient guide · Ingredient reference

    Vitamin C for men: normal functions, intake and the limits of extra dosing

    Adult men generally need 90 mg vitamin C daily. Collagen synthesis and normal immune function do not establish a special testosterone or sexual-performance effect.

    Read the evidence ↓

    Supplement Science Insights Editorial Team

    Published September 23, 2026

    The established roles

    Vitamin C contributes to collagen production, normal immune function and nonheme iron absorption, and acts as a physiological antioxidant. These functions apply to men as well as women. They should not be stretched into proof that more vitamin C improves every outcome marketed as men’s health. [1]

    The adult male reference

    The U.S. RDA for adult men is 90 mg/day from all sources. Smoking adds 35 mg to the reference, giving 125 mg for an adult man who smokes. The adult upper limit is 2,000 mg daily, not a target. Food, fortified drinks, multivitamins and separate tablets all count toward total exposure. [1]

    A claim-review example

    Imagine a supplement supplies 500 mg C and promises higher testosterone because vitamin C is an antioxidant. The physiological premise does not establish that clinical outcome. Assess an actual deficiency or symptom separately, and do not use a men’s label as evidence that a larger dose is necessary. [1]

    Hypothetical example — interpret the stated case, not diagnose or prescribe
    Hypothetical intake referenceVitamin C
    Adult man, nonsmoker90 mg/day
    Adult man who smokes125 mg/day
    A 500 mg productAbove ordinary requirement; extra benefit not implied
    Vitamin C for men: normal functions, intake and the limits of extra dosing — original article outline diagram
    Original editorial diagram of this article’s sections; no product photograph or clinical finding is depicted.

    Sources for this article

    1. Vitamin C - Health Professional Fact Sheet
      Source consulted: 2026-09-20. This is a reference resource, not a claim that we conducted the studies or tested a product.