How do I know if I actually need a Vitamin D supplement?

The most accurate way is through a 25-hydroxy vitamin D blood test. Common signs of low levels include fatigue, bone pain, and frequent illness. Since many people are deficient due to indoor lifestyles and sunscreen use, supplementation is a common clinical recommendation for general wellness and longevity.

About Vitamin D Supreme Guide: Benefits for Bone Health and Longevity

This answer is drawn from the full physician-reviewed guide to Vitamin D Supreme Guide: Benefits for Bone Health and Longevity on the GOAL.MD Vitamin Shop learning hub. Read the full guide for mechanism of action, evidence, dosing, safety, and interactions.

Medically reviewed by Dr. Michael Mimlitz, MD (NPI 1508891870), Chief Physician of GOAL.MD. Physician-supervised telehealth. More at goal.md/answers.