Skeletons, without them life would be a flop, literally. The 206 bones in our body are responsible for keeping us upright, protecting our organs, and producing red blood cells. With the many functions our bones carry out, keeping them healthy is especially important. A key step in keeping ones’ bones strong is making sure to get enough vitamin D, the sunshine vitamin. Not only does vitamin D keep our bones strong, it also allows calcium in the foods we eat to be absorbed by our bodies and incorporated into our bones. Additionally, vitamin D limits the release of the parathyroid hormone, which is responsible for the breakdown of bones. Though the parathyroid hormone is needed for bone remodeling, in excess it can be damaging.

According to Medical News Today article What are the health benefits of vitamin D?, in children, vitamin D deficiencies can cause Rickets, a disease often characterized by bowed legs dues to bone weakness. In adults, vitamin D deficiency often manifests as either osteomalacia or osteoporosis. Osteomalacia is when bones become soft, and osteoporosis is when they become brittle. Both conditions are detrimental to overall health. Mayo Clinic explains that bone breakdown is a constant, naturally occurring process and osteoporosis happens when new bone is not created fast enough to replace the bone that is lost. According to the National Osteoporosis Foundation, nearly 80% of those affected by osteoporosis are women. Additionally, 50% of women over 50 years old break a bone due to osteoporosis. For these reasons, it is especially important for women of all ages to make sure they get enough vitamin D.

In addition to bone health, vitamin D plays a role in cell growth and cell communication, both important in cancer prevention. Medical News Today explains that calcitriol, one of the forms of vitamin D in the body, limits the spread of cancer by preventing the growth of blood vessels in cancerous tissue. Additionally, calcitriol plays a role in preventing cancer from spreading through the body.

The benefits of vitamin D don’t end there. The study Benefits and Requirements of Vitamin D for Optimal Health: A Review found that vitamin D can help prevent  “several bone diseases, muscle weakness, more than a dozen types of internal cancers, multiple sclerosis, and type 1 diabetes mellitus”.

The number of people with vitamin D deficiencies is hard to measure, as there is not a consensus on how much vitamin D is needed on a daily basis. As described by the Scientific American article Vitamin D Deficiency Soars in the U.S., Study Says, estimates range from 20%-75% of Americans being vitamin D deficient. This deficiency can be due to a multitude of factors including location, time, and skin color.

Vitamin D is synthesized by the body when sunlight, specifically ultraviolet-B (UVB) rays, interact with exposed skin. The more skin that is exposed, the more vitamin D is produced. However many factors determine whether the body is naturally able to produce enough vitamin D, including geographic location, exposure time, and skin color.

The Vitamin D Council explains that geographic location is a key factor in vitamin D production. The further one lives from the equator, the less UVB is able to penetrate the atmosphere, due to the angle of the sun. This negative effect is amplified during winter. For example, a person living in Florida is exposed to enough UVB to make vitamin D all year round while a person in Northern Canada is not exposed to enough UVB from October through April to produce sufficient vitamin D.

Time also impacts how much vitamin D your body makes. Early in the day, late in the day, and during much of the winter, the UVB rays enter the earth’s atmosphere at an angle that results in most of them being blocked. Midday, and in the summer are when the most UVB is penetrating the atmosphere, and production of vitamin D is the most efficient.

Skin color also plays a role in vitamin D production. Melanin protects against skin damage by preventing UVB rays from entering the skin. Though this protects the skin, it also prevents vitamin D synthesis. This is why people with darker skin, and more melanin, take more time to produce sufficient vitamin D than those with lighter skin. Age, pollution, and sunscreen can also decrease the efficacy of vitamin D synthesis. These many factors make it difficult to determine just how much time in the sun a person needs to create sufficient vitamin D. However, the Vitamin D Council states that “A good rule of thumb is to get half the sun exposure it takes for your skin to begin to burn to get your vitamin D and expose as much skin as possible.”

In addition to being synthesized, vitamin D can also be consumed. However, according to the Vitamin D Council, most foods do not contain high concentrations of vitamin D, and diet alone is not an adequate supply of this important vitamin. Some of the foods that do have high levels of vitamin D include fatty fish, fish oil, eggs, milk, orange juice, and vitamin D fortified cereals.

Supplements are another source of vitamin D. The Vitamin D Council states the average person who works indoors 5 days a week usually needs supplements to meet the recommended minimum requirement. There are two types of vitamin D supplements: D2 and D3. The Medscape article Vitamin D: A Rapid Review explains that vitamin D3 is the same as what is found in people and fish. It also has a longer shelf life and is more potent than D2. However, D3 is synthesized from lanolin, an oil in wool, while D2 is produced from fungus and yeast. Therefore, D2 is often chosen by vegetarians and vegans. It should be noted that too much vitamin D can cause unhealthy blood calcium levels, so consulting with a doctor is always important when taking supplements. IFANCA has certified a number of vitamin D supplements.

Infants are a group for whom vitamin D supplements are especially important. This is because breast milk is low in vitamin D and it is not recommended for babies to spend much time outside. Mayo Clinic recommends that breastfed babies (fully or partially) be fed liquid vitamin D soon after birth until they are weaned, until they can drink 32 ounces of vitamin D fortified formula a day, or until they are older than 12 months and drink whole cow’s milk.

Just as the sun is key for life, the sunshine vitamin is key for our health, from infancy to adulthood.

Taskeen Khan currently attends UIUC. She has previously written for Huffington Post Teen and Islamic Horizons Magazine. Khan has also won several Silver Keys and honorable mentions in the Scholastic Art and Writing Awards.