What is Vitamin D?
Vitamin D is a vital substance that helps the body absorb calcium and helps maintain bones, muscles, nerves and the immune system. While there are many ways to get vitamin D (through your skin from sunlight, from vitamin D-rich foods such as some mushrooms and salmon and from supplements), if you are not taking a vitamin D supplement, it is very likely that you have vitamin D deficiency. Yes, you.
Vitamin D is one of the four fat-soluble vitamins, meaning it is absorbed with fat and stored in fat cells throughout the body. Although it is called a vitamin, vitamin D it is not technically a vitamin because it is produced in the human body and must be synthesized by the body before it can provide a benefit. It is actually a hormone, providing messaging signals to many parts of the body.
A vast swath of the population is vitamin D deficient. A review of the National Health and Nutrition Examination Survey (NHANES) of nearly 5,000 people over 20 years old who were hospitalized between 2011 and 2012 show that about 40 percent of patients had vitamin D levels less than 50 nmol/L (20ng/ml), below the recommended levels that authoritative sources such as the Endocrine Society and the Vitamin D Council recommend as normal levels. It’s obvious that a significant number of Americans have vitamin D deficiency.
What are the normal levels of vitamin D?
The best blood levels for 25-hydroxyvitamin D range from 30 to 100 ng/ml (75-250 nmol/l). The Institute of Medicine notes that almost all people are sufficient at levels of vitamin D greater than 50 nmol/L (greater than 20 ng/mL), while people with blood levels of vitamin D below 20–25 nmol (8-10 ng/ml) are considered to be at a higher risk for osteoporosis.
Symptoms of vitamin D deficiency
When a person is vitamin D deficient, they are at risk for a myriad of health issues. One of such issues is compromised immune function. Research has now shown that most immune cells have a vitamin D receptor. Other risks include brittle or even misshapen bones and dental cavities. Even autoimmune diseases such as type 1 diabetes, rheumatoid arthritis, multiple sclerosis, and Crohn disease have been correlated with low vitamin D levels.