True or False: Know the Facts About Vitamin D
Allison Bush | June 1, 2012
- 1 True
- 0 False
You are correct! You are incorrect!
True or False: Vitamin D is a hormone.
Vitamin D is actually a hormone. Unllike essential dietary vitamins, it is unique in that it is made in the skin as a result of exposure to sunlight. **Source:** [National Academy of Sciences](http://www.beyonddiscovery.org/content/view.txt.asp?a=414)
True or False: You can never get too much vitamin D.
Vitamin D toxicity is a real thing. Too much (a blood serum level greater than 200 ng/mL) can cause non-specific symptoms such as anorexia, weight loss, polyuria, and heart arrhythmias. More seriously, it can also raise blood levels of calcium, which leads to vascular and tissue calcification, with subsequent damage to the heart, blood vessels, and kidneys. **Source:** [National Institutes of Health](http://ods.od.nih.gov/factsheets/vitamind-HealthProfessional/#h7)
True or False: Sunscreen can block your body's ability to produce vitamin D.
Studies have found that by blocking ultraviolet rays, sunscreen limits the vitamin D we produce (however, it's debated just _how much_ it limits). **Source:** (http://www.nytimes.com/2009/02/17/health/17real.html)_[The New York Times](http://www.nytimes.com/2009/02/17/health/17real.html)_
True or False: Deficiency in vitamin D has been associated with a number of disease, including heart disease, depression, and diabetes, to name a few.
Low vitamin D status has been associated with cardiovascular disease, certain cancers, cognitive decline, depression, diabetes, pregnancy complications, autoimmune diseases. However, [too high levels](http://www.medicalnewstoday.com/releases/245966.php) may also cause a higher mortality rate. **Source:** [Medical News Today](http://www.medicalnewstoday.com/releases/245966.php) [The Huffington Post](http://www.huffingtonpost.com/joel-fuhrman-md/vitamin-d-recommendations_b_800468.html)
True or False: Salmon is a good source of vitamin D.
Very few foods in nature contain vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources. **Source:** [National Institutes of Health](http://ods.od.nih.gov/factsheets/vitamind-HealthProfessional/#h7)
True or False: A serum level of 20 ng/ml is sufficient for 97% of the population to maintain bone health.
Though largely debated, according to the IOM, a serum concentration of 50 nmol/l (20 ng/ml) is sufficient for 97 percent of the population, including bone health as the main endpoint. **Source:** [Harvard School of Public Health](http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/vitamin-d-fracture-prevention/index.html)