Generally, medication, equipment and treatments need to be prescribed by a doctor to qualify as an eligible medical expense. But, the CRA's list of eligible medical expenses doesn't specifically mention socks or other clothing, so it might not hurt to check with the CRA directly.
On a related note, one's total amount of medical expenses needs to be more than 3% of their total income to have an impact on their return. Unless the socks are really expensive or cost just enough to put you over the 3% threshold when combined with your other expenses, you might not find it worth your time to validate it they're claimable.
https://turbotax.community.intuit.ca/replies/2647779