We all know that sunshine is good for us. But what we aren’t always clear about is just how much sunshine we need and at what point our time in the sun starts being bad for our bodies.

Sunshine, when absorbed through our skin, jumpstarts the production of vitamin D, which in turn supports the absorption of calcium. Too little sunshine can be bad for the production of these nutrients in our bodies. And although women’s bodies aren’t so different from men’s in their need for sun, it is important to consider just why women need sunlight everyday and what happens when we don’t get enough of it.

What does the sun do for my body?

As I recently stated in What Happens to Your Body When You Don’t Get Enough Sunlight, sunlight helps your body absorb vitamin D and calcium, which in turn helps with bone growth. You can take in vitamin D through food sources as well, however, sunlight is the strongest path to absorbing enough vitamin D for your body.

Vitamin D production is most connected to the natural light of the sun and its ultraviolet B (UVB) rays. Once exposed to the sun, your skin absorbs these UVB rays, allowing the production of vitamin D to begin. The amount of UVB that your skin is able to absorb is based on many factors, including where you live, cloud cover, and time of day.

We should all strive to get about 10-15 minutes of peak sunshine absorption each day, or at least a few times each week. A consistent flow of sunshine helps maintain levels of vitamin D in your body.

The amount of sunlight your body needs varies based on your skin tone. Darker skin tends to need more sunlight for proper vitamin D production, sometimes up to twice as much. As we age, it becomes increasingly more challenging for the body to absorb vitamin D. So for those over the age of 70, more sunshine is necessary. Additionally, if you’re wearing sunscreen you’ll want to be mindful that it may take longer for your skin to absorb the vitamin D supporting UVB rays.

Once UVB is absorbed into your skin, the body begins its production of vitamin D. As vitamin D is produced in the body, calcium can now be absorbed through the foods you eat. Without vitamin D, the body isn’t able to absorb food-based calcium and begins to take calcium directly from your bones. We don’t want our bodies to remove calcium from our bones as this can cause increased risks of osteoporosis and bone fractures due to calcium deficiencies. Over longer periods of time, vitamin D and calcium deficiencies can cause ongoing symptoms like extreme fatigue, muscle pain, or depression. Be sure to contact your doctor if you are already experiencing these symptoms or begin experiencing any new symptoms as the winter season wears on.

Are Vitamin D Supplements Enough?

It can be more challenging for many of us to get proper sun exposure during the winter months or in cloudier environments. In these cases, it can be helpful to track your sunshine intake (remembering that 10-15 minutes a few times each week is great). If you’re concerned about your UVB absorption, check with your doctor about getting a blood test to identify your vitamin D levels and determine if supplements are necessary.

While vitamin D and/or calcium supplements can support adequate absorption of these nutrients, natural methods of absorption are preferred whenever possible. Consult with your doctor about the level of vitamin D in your bloodstream before taking any synthetic supplements.

There are also vitamin D rich foods, such as salmon and tuna, that offer your body valuable nutrition. (Health.gov, 2015-20) And while you shouldn’t only rely on the amounts of vitamin D in these food sources, they do provide a good base for your body to absorb the nutrient.

Your body needs 800 to 1000 IUs (international units) of vitamin D per day. (Harvard Health, 2008) To put the necessary amount of vitamin D into some context, a standard serving of salmon (about 3 ounces) provides about 600 IUs of vitamin D; one cup of whole milk provides about 120 IUs of vitamin D. (Health.gov, 2015-20) It’s a good idea to pair sunshine with vitamin rich foods, especially in cloudy or air polluted climates where sun absorption may be more challenging.

Too Much Sun or Just Enough

Going beyond the recommended amount of sunlight each day, more than about fifteen minutes per day, can become harmful to the skin and body. The production of vitamin D does not require hours of sun exposure. And although we need sunlight to remain healthy and to provide our skin with necessary nutrients, excessive sunlight exposure (just like the excess of most things in life) can become detrimental to our health. Extensive periods of sun exposure, especially without proper sun protection, can cause issues for your skin and overall health.

When women’s bodies do not absorb enough sunlight, and therefore insufficient amounts of vitamin D, higher risks of heart attack, heart failure, stroke, diabetes or high blood pressure often present later in life. This, according to the Johns Hopkins Medicine, is an evolving understanding of the power of sunlight in women’s bodies. (Hopkins Medicine, 2020) Additionally, those who are pregnant and have low levels of vitamin D are at higher risks of preeclampsia and gestational diabetes.

Finding the right amount of sun exposure and UVB absorption for your skin, within the limits of your geographical location, while balancing vitamin D rich food intake, all begins by taking a step outside or drawing the blinds for a bit of fresh air and sunshine. Remember, just a bit of sunshine can go a long way towards feeding your body the nutrients it needs.

Meet Dr. Savita Ginde

Dr. Savita Ginde is an advocate and thought leader for reproductive health and served as Chief Medical Officer of Planned Parenthood of the Rocky Mountains for over 13 years. And, until very recently, she served as the Chief Healthcare Officer for STRIDE Community Health Center where she oversaw all of STRIDE’s healthcare services and led their COVID-19 vaccination efforts.