A human body produces vitamin D as a response to sun exposure. A person can also boost their vitamin D intake through certain foods or supplements.
Despite its name, vitamin D is not a vitamin, but a prohormone, or precursor of a hormone.
Vitamins are nutrients that the body cannot create, and so a person must consume them in the diet. However, the body can produce vitamin D.
In this article, we look at the benefits of vitamin D, what happens to the body when people do not get enough, and how to boost vitamin D intake.
During sun exposure, a person’s body produces vitamin D.
Vitamin D has multiple roles in the body. It assists in:
- promoting healthy bones and teeth
- supporting immune, brain, and nervous system health
- regulating insulin levels and supporting diabetes management
- supporting lung function and cardiovascular health
- influencing the expression of genes involved in cancer development
Read on to find out about these roles in more detail:
1. Healthy bones
People need vitamin D to allow the intestines to stimulate and absorb calcium and reclaim calcium that the kidneys would otherwise excrete.
Vitamin D deficiency in children can cause rickets, which leads to a severely bowlegged appearance due to the softening of the bones.
Similarly, in adults, vitamin D deficiency manifests as osteomalacia, or softening of the bones. Osteomalacia results in poor bone density and muscular weakness.
2. Reduced risk of flu
However, the authors also looked at other studies where vitamin D did not have this effect on flu and flu risk.
Further research is, therefore, necessary to confirm the protective effect of vitamin D on the flu.
3. Healthy infants
The American Academy of Allergy Asthma and Immunology (AAAAI) suggest that evidence points to a connection between low vitamin D exposure and an increased risk of allergic sensitization.
An example of this is children who live closer to the equator and have lower rates of admission to hospital for allergies plus fewer prescriptions of epinephrine autoinjectors. They are also less likely to have a peanut allergy.
The AAAAI also highlight an Australian study of egg intake. Eggs are a common early source of vitamin D. The children who started eating eggs after 6 months were more likely to develop food allergies than children who started between 4–6 months of age.
4. Healthy pregnancy
Doctors also associate poor vitamin D status with gestational diabetes and bacterial vaginosis in pregnant women.
It is also important to note that in a 2013 study, researchers associated high vitamin D levels during pregnancy with an increased risk of food allergy in the child during the first 2 years of life.
Although the body can create vitamin D, a deficiency can occur for many reasons.
Skin type: Darker skin, for example, and sunscreen, reduce the body’s ability to absorb the ultraviolet radiation B (UVB) rays from the sun. Absorbing sunlight is essential for the skin to produce vitamin D.
Sunscreen: A sunscreen with a sun protection factor (SPF) of 30 can reduce the body’s ability to synthesize the vitamin by 95% or more. Covering the skin with clothing can inhibit vitamin D production also.
Geographical location: People who live in northern latitudes or areas of high pollution, work night shifts, or are homebound should aim to consume vitamin D from food sources whenever possible.
Breastfeeding: Infants who exclusively breastfeed need a vitamin D supplement, especially if they have dark skin or have minimal sun exposure. The American Academy of Pediatrics recommend that all breastfed infants receive 400 international units (IU) per day of oral vitamin D.
Although people can take vitamin D supplements, it is best to obtain any vitamins or minerals through natural sources wherever possible.
Symptoms of vitamin D deficiency may include:
- regular sickness or infection
- bone and back pain
- low mood
- impaired wound healing
- hair loss
- muscle pain
If Vitamin D deficiency continues for long periods, it may result in complications, such as:
- cardiovascular conditions
- autoimmune problems
- neurological diseases
- pregnancy complications
- certain cancers, especially breast, prostate, and colon.