Many years ago, I started taking an extra Vitamin D supplement as part of my daily diet. At first, I could not take more than 500-1000 IU of vitamin D daily - because I just did not feel right or well if I took more. However, over time - my body got use to taking higher doses of Vitamin D and at present I am supplementing with a single 5000 IU pill each day. I did not start taking Vitamin D for no reason at all, but instead - after watching family members die horrible deaths from cancer over the years, I decided to try and do something proactive to hopefully improve my odds at suffering the same fate.
Like with everything else in life, there are pros and cons to taking a high dose Vitamin D supplement each day. On the pros side, there are dozens of studies that show that folks with high levels of Vitamin D in their bloodstream are less likely to suffer some of the most common forms of cancer such as breast and prostate than people who have low Vitamin D concentrations. Another thing on the pros side of taking a daily Vitamin D supplement is that in it's pure form after kidney metabolism, Vitamin D is converted into a powerful hormone that the body seems to need in abundance. This pure and powerful form of Vitamin D not only helps the body's immune system fight sickness and disease - but it also seem to have a calming effect on stress and mood as well.
On the cons side of taking a daily Vitamin D supplement there are those nagging questions in the back of the mind that cause some people to ask - if they are overdosing themselves on too much of a good thing? With low levels of Vitamin D supplementation recommended at the 400-1000 IU level by the US government, there are always going to be some concerns that taking a fat soluble vitamin like D will eventually lead to a fatal overdose. It's pretty clear from new and old research that those concerns are not valid and it would help save many lives each year - if the US and other federal governments around the world - got with the program and increased the recommended daily level of Vitamin D intake.