Brighter Days, Darker Nights

Brighter Days, Darker Nights

Pregnancy, Birth, Postpartum and Childhood

Vitamin D drops for newborns?

with relevance for Vitamin D supplementation at any age

Nikko Kennedy's avatar
Nikko Kennedy
Apr 30, 2026
∙ Paid

Today’s post is about Vitamin D supplementation for babies, with relevance for Vitamin D supplementation at any age.

Enjoy!

🌞 Brighter Days, Darker Nights 🌚 is a reader-supported publication by Nikko Kennedy.

a baby laying on a bed with a white blanket
Vitamin D for babies! What’s the best way to get it? Thank you Laura Ohlman for the perfect photo for this post!

Babies are born equipped to absorb UV light much more rapidly than adults through two mechanisms:

  1. Lower melanin levels, so they have less shielding

  2. Higher vellus hair content (the super soft, uncolored hair or “peach fuzz”), which may absorb UV light approximately 250x as fast as normal hair

These physiological conditions seem to allow babies to meet their UV light requirements in a very short amount of time without experiencing dehydration, heat fatigue or sunburn

In un-supplemented individuals, solar-derived Vitamin D is thought to make up approximately 90% of serum levels1.

And yet it is common to find even highly educated researchers making claims such as “low compliance…

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