Does the sun give us enough vitamin D?

Vitamin D, or the “sunlight vitamin,” is a prominent constituent of a healthy lifestyle. During these harsh months of winter, however, sunlight is in short supply and most Canadians tend to leave home early while it’s still dark out, and return when it’s even darker. Unfortunately, this leads to very little intake of vitamin D. When the human skin is exposed to sunlight, it synthesizes vitamin D through the use of cholesterol, and stores any surplus in the form of fat. This source accounts for 80-to-90 per cent of the total intake, although some styles of food and dietary supplements can also be an alternative. Since vitamin D can be produced by mammals within their bodies and is not a necessary dietary factor, it acts more as a hormone than a vitamin.

Vitamin D is crucial for regulating the absorption of calcium. When the bloodstream lacks calcium, the body will extract it from the bones. Vitamin D doesn’t just help prevent this but also keeps bones, teeth, and muscles healthy and strong. The adverse effects of a lack of vitamin D can result in rickets within children where bones can be softened or distorted. Moreover, vitamin D can also be used for treating weak bones, a condition known as osteoporosis, as well as bone pain, known as osteomalacia. In certain diseases such as osteogenesis imperfecta, where bones are especially brittle or easily broken, vitamin D is recommended to take. Not to mention, it can be a useful treatment for individuals at risk of falls or fractures and even other diseases such as kidney failure that may cause bone loss. Muscles also require calcium to prevent chronic muscle aches, cramping, and weakening over time.

The required amount for the vitamin depends on the age of the individual, as well as other medical factors. The recommendation of around 600 IU (international units) or 15 micrograms per day is the recommended dose for the majority of people. For undergraduate students, the daily upper level for vitamin D intake is around 4,000 IU and 2,500 mg for calcium. However, some studies, when taking into account the amount of sunlight exposure, recommend a higher daily intake of 1000-to-4000 IU or 25-to-100 micrograms. Vitamin D intake is recommended to be received through the food you eat because sunlight may cause additional harmful side effects due to UV rays.

There are two types of vitamin D that are necessary for the body. The D3 variant is found in abundance within the flesh of fatty fish, fish liver oils, and in small amounts within beef liver, cheese, and egg yolks. The D2 variant can be mostly found within mushrooms. There are also certain types of foods that are fortified with vitamin D, including milk, salmon, tuna, egg yolks, and sardines.

Options in food are usually limited, especially on UTM’s campus. As an alternative, renowned dietician Nazima Qureshi states that, “With minimal sunshine, and not too many foods with vitamin D, supplements can be a smart option.” Dietary supplements containing vitamin D can always be consumed by adding it to food or taken in the form of pills.

It’s also important to realize that too much of anything, including vitamins, can be harmful to your health. Staying within your recommended limit is important. If you are not sure what your recommended limit is then, perhaps, a trip to the doctor’s office is necessary to find out.