To vitamin D? Or not to vitamin D? That is the question.
I’ve heard opinions from all sides, ranging from the people who say that supplementing has saved their health to other health professionals who say supplementing with vitamins and minerals is just quackery.
As I have done more and more reading about vitamin D, I realized how lucky I was that there was this much research about it. And even more, how much arguing there is about it. Like all good scientists, there is a lot of splitting hairs about what good this vitamin actually does.
Research on Vitamin D
The Harvard School of Public Health estimates that 1 billion people worldwide don’t have enough vitamin D going through their blood and we are seeing a resurgence of bone diseases such as Rickets. Typically it only takes 15 minutes/day in direct sunlight to fulfill our need for vitamin D.
If we are encountering these problems then why wouldn’t you just supplement with vitamin D or just sit out in the sun for 15-20 minutes?
How Much Do You Need?
So how much vitamin D are we supposed to take? The recommended daily intake of vitamin D according to the Institute of Medicine (IOM) is 600 International Units (IU) / day with an upper allowance of 4000 IU’s per day.
I was surprised, that seemed to be a really small amount. Walking through the aisles at the local pharmacy you can see that they sell vitamin D in assorted concentrations from 500 IU / pill all the way up to 10,000 IU / pill; two and a half times the maximum daily allowance. That’s odd.
Is Toxicity a Concern?
So, out of curiosity I wanted to see how much vitamin D it would take to cause toxicity. And I found that this is actually a really safe supplement to take. It requires an intense amount of vitamin D for a very prolonged period of time to produce toxic effects. According to the Merck Manual, in order for an adult to experience vitamin D toxicity they would have to ingest/absorb 50,000 IU (fifty thousand, not a typo) per day for several months.
Vitamin D seems to be involved in the immune system, skeletal system, intestines, kidneys, parathyroid glands, and the pancreas. It mostly has to do with Calcium absorption and transport, and stimulates the production of insulin in the pancreas.
So, if you live a mostly indoor lifestyle with very little exposure to direct sunlight, then perhaps supplementing with vitamin D isn’t such a bad idea.
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