User talk:67.169.252.230

Vitamin D edit
The text and ref you added to vitamin D was reverted. The ref was to a small clinical trial = primary research. It was wrong to describe it in the text as a meta-analysis. David notMD (talk) 13:38, 12 January 2019 (UTC)

Retinol
I deleted three references you had added to the Epithelial cells section. The references were not relevant to the text. The references were older than Wikipedia likes to have for medicine/health articles. One was based on animal research. See WP:MEDRS for explanation of what are considered reliable sources in this arena: reviews, meta=analyses, systematic reviews, etc. Not individual clinical trials. The reference format was not acceptable. For referencing, search at PubMed for appropriate articles, then copy the PMID number and insert that number at https://tools.wmflabs.org/citation-template-filling/cgi-bin/index.cgi This will auto-generate a ref in one of the accepted formats. David notMD (talk) 14:00, 12 January 2019 (UTC)