Can You Get Vitamin D Through a Window? (Boost Tips)

Can You Get Vitamin D Through a Window? (Boost Tips)

Vitamin D is crucial for human health since it supports healthy bones and reduces the risk of falls, particularly in elders. It also lowers the risk of breast cancer and protects against cardiovascular disease. Finally, it is also connected to the mood and helps you cope with depression.

The only way for your body to produce vitamin D is to exposure to direct sun rays. Only that way, calcium absorption from food is possible, allowing for building and maintaining bones. The question is can you get vitamin D through a window. Unfortunately, you can’t, since most windows block UV rays. Let’s take a look.


Can You Get Vitamin D Through a Window?

Vitamin D Benefits

Vitamin D Benefits

Vitamin D (sunlight vitamin) is one of the essential fat-soluble vitamins our body needs, but it is impossible to produce it without exposure to the UV sun rays. You need to spend about 15 to 20 minutes a day in the direct sun to let your body start vitamin D production.

In such conditions, your liver and kidneys allow converting the vitamin D inert form into an active D3 vitamin your body can use. However, you can’t get it during winter if you live in a state above 35 degrees latitude. The problem is in the angle of sun rays reaching the ground during that season.

Vitamin D is necessary for numerous purposes and has different roles in the human body’s functioning, such as:

  • Supporting bone health, particularly in kids and elders
  • Keeping the cardiovascular system healthy
  • Supporting neuromuscular function
  • Protecting the body against Diabetes Type 1 and 2
  • Helping in mood-regulating and preventing depression
  • Supporting a healthy immune response
  • Lowering the risk of some cancer types, primarily breast cancer
  • Preventing obesity
  • Protecting against COVID-19

Keep in mind that the body of people with darker skin requires three times more vitamins than those with lighter skin. The reason is higher levels of melanin, which their bodies contain and reduce natural vitamin D synthesis.

It is estimated that 30% to 40% of adult Americans suffer from vitamin D deficiency, but Afro-Americans have 15 to 20 times more chances of being in deficit. You are prone to vitamin D deficiency as a result of inadequate absorption of nutrients if you are:

  • Elderly
  • Obese
  • Dark-skinned
  • Consume a poor diet
  • Suffer from digestive diseases, like celiac or Crohn’s
  • Have an issue with liver or kidney disease
  • Have a food allergy

Without this vitamin, your body can’t regulate the calcium and phosphate level, and calcium absorption becomes impossible. As a result, people may have an issue with bones, teeth, and muscles. Vitamin D deficiency is a severe condition that leads to:

  • Porous, fragile bones
  • Rickets and osteomalacia
  • Joint pain
  • Depression
  • Fatigue


Can You Get Vitamin D Through a Window?

Can You Get Vitamin D Through a Window

Sunlight has two ultraviolet ray types:

  • UVA (ultraviolet A) – These rays are responsible for premature aging, wrinkles, and cancer development.
  • UVB (ultraviolet B) – They cause redness and sunburn but also trigger vitamin D synthesis.

As you know, most windows in homes and vehicles come with UVB blockers. As a result, it is impossible to start vitamin D synthesis while sitting in front of a sunny window. The only thing you will get is to expose your skin to harmful UVA radiation.

There is one more issue! Your skin can’t absorb vitamin D when using sunscreen since it blocks the UVB rays. Scientific results show that a sun protection factor (SPF) of 15 reduces vitamin D production by at least 90%.

Therefore, the best option you have is to go for a walk for about 20 minutes in the morning or afternoon and then apply sunscreen.


Ways to Boost Vitamin D Synthesis

Ways to Boost Vitamin D Synthesis

1. Sunshine

Even though overexposure to the sun can harm your body and cause premature aging and skin cancer, you shouldn’t avoid it altogether.

One of the reasons is vitamin D since the sun is crucial for its synthesis. If you want to avoid harmful effects and get the best of the sun exposure, you should spend half an hour in the direct sun in the morning or afternoon.

2. Food

Besides getting this vitamin through sun exposure, you can intake it with food. Unfortunately, very few foods contain it, but you can get it from:

  • Fatty fish, like salmon, tuna, sardines, swordfish, and herring
  • Cod-liver oil
  • Beef and beef liver
  • Egg yolks
  • Mushrooms
  • Cheese
  • Butter and milk

Remember that plant-based foods, like cereals and orange juice, contain a certain amount of vitamin D. However, it is almost impossible to get it enough from these ingredients.

3. Supplements

When sun exposure is limited, and you can’t intake enough vitamin D through your diet, you have an option to make it up with supplements. You can go to the doctor and ask for a 25-hydroxy vitamin D blood test to measure its level in your body.

A typical serum level is 20 to 50 ng/mL, while a value below 20 ng/mL shows that you are deficient. Remember that these results in Afro-Americans are naturally below 10 ng/ml.

An adult, including pregnant women, needs 600 IU (15 mg) of this vitamin daily on average. Adults older than 71 have higher needs and should intake at least 800 IU (20 mg) daily.

Be careful with supplementation! You can intake up to 1,000 IU (25 mg) of vitamin D every day, but doses over 4,000 IU (100 mg) daily are potentially toxic to the liver.


Ways to Boost Vitamin D Levels

Ways to Boost Vitamin D Levels

1. Check the vitamin D level in your body

The best way to check vitamin D levels in your body, particularly during winter, is to ask your doctor to do a blood test. Only that way can you determine whether you need supplements during this season.

2. Sun exposure

The sun is a steady and entirely natural vitamin D source. Spending time exposed to UV rays will provide the body with necessary vitamin D. As I have already mentioned, it is impossible to get the full effect by sitting next to the window since the glass blocks necessary UVB rays.

So, you should take advantage of the sun and increase the vitamin D level in your body by spending time outdoors. The best option is to spend some time in the direct sun while walking, jogging, or riding a bicycle.

However, you should know how long to stay exposed without harmful effects. According to the information you can find at the Vitamin D Council site, the necessary exposure to the UV rays is:

  • 10 to 20 minutes for light skin persons
  • A few hours for dark skin persons

3. Exposed skin

Exposing more significant body parts to the sun will increase vitamin D production. So, sunbathing at least 10 minutes a day is better than spending hours outdoors while only your face and hands are exposed.

4. Skin color

As I have already mentioned, darker skin will increase the risk of vitamin D deficiency. The reason is natural pigment melanin that has similar effects as sunscreen. It absorbs UVB sun rays and prevents triggering vitamin D production.

5. Elevation

Since the atmosphere is thinner at higher altitudes, you will get more vitamin D while spending time in the mountain. On the other hand, you have greater chances of suffering from vitamin D deficiency if you live on the plain.

6. Sunscreen

Applying sun protection prevents sun rays from reaching your skin. For instance, a sunscreen with SPF 30 absorbs almost 98% of the UVB sun rays. Therefore, it is recommended to spend at least ten minutes a day exposed to sunlight without applying sunscreen.

7. Time of day

Be aware that your skin gets more UV rays during the middle of the day, allowing higher vitamin D production.

However, you can avoid walking in the brightest sun and spend more time outdoors in the morning or evening. That way, you will prevent harmful UV rays’ effects and allow vitamin D production at the same time.

8. Check the air pollution level in your city

Nowadays, you can effortlessly check the air pollution level in your region and city after visiting It is crucial information since pollution significantly influences vitamin D production in your body.

Since polluted air absorbs UVB sun rays, your skin will get less of them. For instance, San Diego and Los Angeles are in regions with a high level of sunlight throughout the year. Still, high levels of air pollution often cause a vitamin D deficiency in citizens.

9. Indoor tanning bed

Some researches show that spending time in an indoor tanning bed can increase vitamin D production in your body.

However, you shouldn’t spend more than half the time necessary for your skin to burn. Plus, it is recommended to avoid those emitting high-intensity UVA lights and use only low-pressure UVB beds.



You can get enough vitamin D only through sun exposure. After that, your body will use it to absorb the calcium from food and keep you healthy.

Since most windows in your home and car block UV rays, you can’t get enough vitamin D by sitting next to them. The only way to get enough vitamins is to expose yourself to direct sunlight or take supplements regularly.

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