How much do you know about the ‘sunshine vitamin’? Commonly known as vitamin D, getting enough is essential for a healthy, functioning body. Receiving it naturally from the sun is a great perk.

Vitamin D is made when bare skin is exposed to UVB rays from the sun. The absorption can be decreased by clouds, smog, older age, clothing, and seasons when UV rays are weaker. For example, our winters tend to be a season where the sun’s rays are too weak for proper absorption. Also, your skin can’t make vitamin D from the sun shining through a sunny window. Unfortunately, UV rays can cause skin cancer, so it’s important to limit time in the sun without sunscreen. On the other hand, when sunscreen is applied correctly, it can reduce vitamin D absorption by 90%.

A result of vitamin D deficiency can lead to osteoporosis. It is a disease that causes weak and brittle bones, making them easier to break. Osteoporosis is also sometimes called a “silent” disease because there are typically no symptoms. You may not know you have osteoporosis until you break a bone. Hidden signs include weak or soft bones that break or change in shape and weakened muscles.

However, with enough vitamin D, our bodies can absorb and retain calcium, which your body needs for building and maintaining healthy bones. You can’t absorb calcium without vitamin D present. Furthermore, vitamin D is responsible for increasing intestinal absorption of magnesium and phosphate and many other biological effects. Vitamin D also regulates many other cellular functions in your body. Its anti-inflammatory, antioxidant, and neuroprotective properties support immune health, muscle function, and brain cell activity.

The average adult needs 10-30 minutes in the sun a few days a week to get the recommended amount of vitamin D. Worried about no sun today? Relax, it is also present in food. Although, due to the limited amount of food that naturally contains vitamin D, some foods, such as milk, breakfast cereals, yogurt, and orange juice, are fortified with it.

Fortunately, over-the-counter vitamin D supplements are available. Supplements should be limited to 4,000 IU (100 mcg) daily unless monitored under the supervision of your doctor. In general, most adults require a supplement in the winter.

It is rare to have toxic vitamin D levels from fortified food and sun exposure. Toxicity typically only occurs from taking supplements. Symptoms of toxicity are loss of appetite, weight loss, irregular heartbeat, and hardening of blood vessels that could damage the heart and kidneys.

Talk to your provider about your levels of the ‘sunshine vitamin’ to see if supplements are needed for you or your loved ones.