Winter Weather and its Effect on the Body’s Synthesis of Vitamin D

Amanda Reichardt- Staff Writer

Vitamin D has two main forms: D2 and D3. These two forms differ in chemical structure and source but not in general metabolism or function in the body.
D3 is provided in the diet primarily by animal sources like liver and eggs. Some plant and fungus foods provide D2, such as shitake mushrooms. There are foods in the United States fortified with vitamin D like milk, yogurt, cheese, butter, some juices, margarine, some breads and breakfast cereals mainly in the form of D3. Supplements also provide the body with the vitamin.
The sun also plays a role in all of this. Vitamin D3 is made in the body as a steroid in the skin’s sebaceous glands, which then secrete the steroid onto the skin’s surface to be reabsorbed into the many layers of the skin. When a person is exposed to the sun, its rays penetrate the skin where skin cells absorb energy. The event causes our body to synthesize vitamin D3 over a period of several hours to a few days.
The rumors are true that residents of the snow filled regions of the northern US are at a greater risk for developing vitamin D deficiency. People who are also at risk include the elderly, those pregnant or lactating, who limit their exposure to the sun, who live in geographic locations at higher latitudes, people who have a darker skin tone and people with excess body fat. Overall, low vitamin D can be found across all age groups, ethnic backgrounds and geographic locations but there is no reason to panic. It is important to make oneself aware.
Deficiency is a major concern that puts one’s health at risk. According to the Center for Disease Control and Prevention, 67 percent of U.S. citizens had sufficient vitamin D levels, 24 percent had a risk of inadequacy and 8 percent were at risk for deficiency. Adverse health effects can be caused by a lack of vitamin D such as rickets, osteomalacia (bone mineralization), cognitive impairment in older adults, asthma in children, cancer and cardiovascular disease. The Daily Value on food and supplement labels for vitamin D is 400 IU. It is recommended to consume your vitamins through the food you eat, rather than through supplements. Treatment for vitamin D deficiency is through supplementation after speaking to a health professional.