can you get vitamin d through a window

Can You Get Vitamin D Through a Window? Uncovering the Truth Behind Sunlight and Vitamin D Synthesis


The quest for sufficient Vitamin D levels has often led to the question: “Can you get Vitamin D through a window?” This inquiry is more than just curiosity; it’s a crucial aspect of understanding how we can maintain optimal health through natural means.

The Science of Vitamin D Synthesis

Vitamin D, often dubbed the ‘sunshine vitamin’, is unique as it is produced in our skin in response to sunlight, specifically UVB rays. Dr. BreAnna Guan, a naturopathic physician, explains, “The body produces vitamin D when exposed to UVB rays, which are most abundant during summer months”​

​This process is not as straightforward as one might think, as several factors, including the type of glass in windows, can influence it.

Can Windows Transmit UVB Rays?

Most ordinary glass windows block the majority of UVB rays, essential for Vitamin D synthesis. While specialized glass, like low-E glass, allows more UVB rays to pass through, it is still not sufficient for Vitamin D production​​. Nature Made® confirms that glass absorbs 100% of UVB rays, nullifying the possibility of Vitamin D synthesis through a window​

The Role of Diet and Supplements

With the limitation of UVB transmission through windows, the focus shifts to diet and supplements. Dr. Guan advises a three-pronged approach – sunlight exposure, nutrition, and supplementation – for optimal Vitamin D levels​​. Mindbodygreen highlights the importance of high-quality vitamin D supplements to achieve sufficient Vitamin D status​

Vitamin D: Beyond Bone Healt

Vitamin D’s role extends far beyond bone health. It’s crucial for maintaining muscle function, immune system function, and heart health. It’s also a vital player in longevity and mood support, with studies indicating its significant impact on living longer, healthier lives​

Expert Opinions and Scientific Consensus

Dr. Guan suggests 10 to 15 minutes of sun exposure is adequate for Vitamin D synthesis, emphasizing the need for direct sunlight over exposure through windows​

​. The consensus among experts is clear: while sunlight through windows contributes to environmental comfort, it does not facilitate Vitamin D production in the skin.


In conclusion, while sunlight is a primary natural source of Vitamin D, windows significantly diminish its effectiveness in Vitamin D synthesis. The incorporation of a balanced approach involving direct sun exposure, diet, and supplementation is essential for maintaining healthy Vitamin D levels.


  1. BreAnna Guan, ND, Boston-based Naturopathic Physician.
  2. Mindbodygreen – Expert Insights on Vitamin D.
  3. Nature Made® – Health Resources.

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