“The best vitamin for making friends is B-1”

“The best vitamin for making friends is B-1 (be one)” is a pun that has been printed on many images. The joke was published in Boys’ Life magazine in October 1977.
 
     
Google Books
October 1977, Boys’ Life, “Think & Grin,” pg. 86, col. 2:
Billy: What’s the best vitamin for making friends?
Bobby: Bl!—Kathy O’Neill, Chicago, Ill.
 
3 March 1993, Des Moines (IA) Register, ad supplement, pg. ?:
The best vitamin for making friends, B-1.
 
12 August 1995, Seattle (WA) Times, “Some Words of Wisdom” by Dale Turner, pg. C4:
Best vitamin for making friends: B 1.
 
Google Books
Pun and Games:
Jokes, Riddles, Daffynitions, Tairy Fales, Rhymes, and More Wordplay for Kids
By Richard Lederer
Chicago, IL: Chicago Review Press
1996
Pg. 86:
The best vitamin for making friends is B-l.
 
Twitter
QuotesBlog‏
@quotesblog
“The best vitamin for making friends is B1.”—seen at
Rooster’s
10:23 AM - 25 Jul 2007
 
Twitter
David Damore‏
@Admore
Mackay’s Moral: The best vitamin for making friends is B-1.
6:45 AM - 21 Aug 2008
 
Google Books
Amish Proverbs:
Words of Wisdom from the Simple Life
By Suzanne Woods Fisher
Grand Rapids, MI: Revell
2010
Pg. 163:
The best vitamin for making friends is B1.
 
Google Books
Mandala-365:
A Daily Workbook of Holistic Healing
By Dr. M. P. Khan NMD, MD
Bloomington, IN: Balboa Press
2016
Pg. ?:
“The Best Vitamin for making friends….B1”