What is the side effect of taking describe vitamin D tablets once per week

Hello Anon

Thank you for writing.

Vitamin D is not something the body makes so about 20 mins of sunshine every day should do the trick or a daily supplement.

There is no "side effect" to taking Vitamin D once a week if you're getting sunshine. About 600 IU per day is recommended for healthy bones. A vitamin D deficiency could result in poor bone health and fatigue.
Best,
Susan