Vitamin D: Everything You Need to Know

Question: What is the role of vitamin D? Do you have a deficiency?

Dr. Leon Li, Emergency Medicine Physician, shares his expertise with you…

What is the role of vitamin D?

The primary role of vitamin D is to promote the absorption of calcium along with the formation and enhancement of bone. Some studies have found that the vitamin D deficiency may also be linked to common diseases such as cancer, hypertension, cardiovascular diseases, and diabetes.

What are the symptoms of vitamin D deficiency?

Adults with vitamin D deficiency may experience osteoporosis, bone pain, muscle weakness, bone fractures, or difficulty walking. Infants and children with vitamin D deficiency may experience rickets, bone softening, muscle weakness, or reduced exercise capacity.

How can we acquire vitamin D?

Our daily food intake contains low amounts of vitamin D. The primary way that humans acquire vitamin D is from its synthesis in our skin as a result of exposure to ultraviolet radiation from sunlight. This process is highly efficient. In general, it only takes 10 minutes for our bare upper body and face, when exposed to the sunlight directly, to synthesize 200 units of vitamin D. However, long exposure doesn’t produce excessive amounts of vitamin D, and could potentially cause other adverse effects.

Why do we need vitamin D supplements?

Due to weather and the impact of different geographical latitudes, different intensity from the sun and the different skin color, many people cannot use sunshine alone to synthesize vitamin D –  especially infants, disabled people and the elderly. For those  over 70, the capability to synthesize vitamin D is also greatly reduced.

How much vitamin D should we consume per day?

Babies under one year old are recommended to take 400 units of vitamin D a day. Infants who are fed formula milk don’t need add vitamin D because formula is usually fortified with vitamin D. However, those infants who breastfeed or partially breastfeed need to add vitamin D. People between the ages of 1 to 70 are recommended to have 600 units of vitamin D a day, with 800 for those over 70. People with special health concerns, such as patients with malabsorption, are suggested to have a greater amount of intake.

Can an excess of vitamin D be toxic to you?

The toxic dose of vitamin D is relatively high, making vitamin D poisoning rare. The tolerable upper intake level of vitamin D for adults is 4000 units a day, 1000 for infants 0-6 months old, and 1500 for infants who are 6-12 months old.

References:

www. uptodate.com