Vitamin D and Winter

Winters are long and grey. From October to March, sunlight is scarce, and children's bodies struggle to produce enough Vitamin D. This is a scientifically established fact: winter Vitamin D deficiency is especially common at northern latitudes.

Why Vitamin D Matters So Much

Vitamin D is not an ordinary vitamin but a hormone-like substance that affects nearly every organ system. It is essential for:

Bone health: Helps absorb calcium. Without enough Vitamin D, even abundant calcium is not absorbed.
Immune system: People with Vitamin D deficiency get respiratory infections more often.
Brain development: Research shows a link between Vitamin D and children's cognitive development.
Mood and sleep: Low Vitamin D levels are linked to melancholy and sleep disturbances.

Why Vitamin D Deficiency Is More Common in Winter

There are several reasons:

Geography: At 39°-43° N latitude, winter sunlight is too weak for Vitamin D synthesis.
Climate: In winter, children spend little time outdoors, and when they do, they are heavily covered.
Skin coverage: Using sunscreen for sun protection (which is correct!) also limits Vitamin D synthesis.
Diet: Few foods naturally contain Vitamin D — fish oil, fatty fish, egg yolks. In many families, these are rarely daily staples.

How Much Vitamin D Is Needed

The American Academy of Pediatrics (AAP) recommends:

Newborns to 1 year: 400 IU daily (10 mcg).
Children 1+ years: 600 IU daily (15 mcg).
Teens 14+ years: 600-800 IU daily.

These doses are the minimum. Some doctors prescribe higher doses for children with deficiency based on blood test results.

How to Ensure Vitamin D in Winter

Three main paths:

Sunlight: Even in winter on sunny days, try to go outside with your child for 15-20 minutes. Leave the face and hands exposed (remove gloves briefly).
Food: Add fatty fish (salmon, sardines), egg yolks, and Vitamin D-fortified dairy.
Supplements: During winter months, Vitamin D3 drops are a practical solution. Liquid form is especially easy to dose precisely.