The best Vitamin D3 supplement for the price is designed by Synergistics and can be purchased at Ultralife for a 10% lifetime discount if you mention that you need it for leaky gut syndrome. If purchased online, just list leaky gut as the advisor to get the discount. This is a 60-day supply at one capsule per day.

Vitamin D3 Supplements

Vitamin D3 5000 IU 60 capsules by Synergistics

Vitamin D3 Videos

The Very Delightful Vitamin D by David Perlmutter, M.D.

Vitamin D Deficiency Part 1 by Richard M. Cooper, M.D.

Vitamin D Deficiency Part 2 by Richard M. Cooper, M.D.