What Happens to Your Vitamin D Levels as You Age?

Verywell Health • February 23, 2026 • health

Key Points:

Vitamin D levels tend to decline with age due to reduced sunlight exposure, decreased skin production of vitamin D precursors, and potential declines in liver and kidney function.
Aging skin produces less vitamin D, and older adults often spend less time outdoors, which limits natural vitamin D synthesis.
The liver enzyme 25-hydroxylase, important for activating vitamin D3, may decrease with age, though this effect has been observed mainly in animal studies.
To boost vitamin D, older adults should safely increase sunlight exposure, but avoid sunburn and consider medication-related sun sensitivity that limits time outdoors.
Vitamin D supplements can help, especially in low-sunlight regions, but should be taken under medical guidance to avoid toxicity