Canada vs US dose check · vitamin C · Health Canada licences read 2026-11-12

How many Canadian vitamin C supplements recommend more than the US limit?

1,175 of 14,871 Canadian-licensed products (8%) recommend a daily amount of vitamin C at or over the NIH adult upper limit of 1,800 mg, and 2,583 (17%) recommend half the limit or more. The median licence recommends 10% of the limit at its highest dose. These are label facts, not a statement that any product is unsafe.

Not medical advice. This page compares what a Canadian licence authorises a company to recommend with a US population intake limit. It does not say any product is safe or unsafe, it does not say anyone takes that amount, and it gives no dose recommendation. Ask your pharmacist or doctor about your own supplements.

What does the licence data show for vitamin C?

30,068 Canadian licences list vitamin C; 14,871 have a recommended adult dose that can be read as a number of tablets or capsules a day. The US limit used is 1,800 mg a day for adults (14-18 years), which the NIH sets for total intake.

Measure	Licences
List vitamin C	30,068
Could be checked	14,871
Half the limit or more	2,583 (17%)
At or over the limit	1,175 (8%)
Share of limit, 90th percentile	69%

4 licences with a share above ten times the limit are counted above but not used for the median or 90th percentile; they are more often a data-entry or unit issue in the licence record.

Why could some vitamin C licences not be checked?

A licence cannot be checked when its recommended adult dose is a liquid or powder amount, is not stated per day, is missing, or lists an amount in a unit the check cannot read. 15,197 licences listing vitamin C fall in these groups.

Reason	Licences
dose unit is not a countable dosage unit	9,889
frequency is not stated per day	2,839
no adult dose	2,017
dose or frequency is missing	412
ingredient amount or unit not readable	25
no recommended dose on the licence	15

Where can you look up one product?

Open the check and type a product's name to see its own recommended maximum against the limit. See the Health Canada Licensed Natural Health Products Database for the licence and the NIH dietary reference intakes for how the NIH sets its limits.

Compiled and checked by Vincent Wesley Couey (ORCID 0009-0005-6869-308X) from the Health Canada Licensed Natural Health Products Database, downloaded 2026-11-12, and the NIH Office of Dietary Supplements. Not an official source.