In the year 2009, the recommended dietary allowance (RDA) or the required amount of Vitamin D that should be taken by the human body was found out to be 200 to 400 IU or International Units each day. This is enough in order to prevent bone related diseases like osteoporosis and rickets. This study was accepted by the medical world.

On the other hand, some medical professional say that the RDA is sufficient enough to prevent bone deterioration but it is not enough in order to fully protect the bones. Take for example the RDA of 500 calories a day for each individual. It will keep you from starving and from eminent death but it does nothing more than that. Vitamin D supplementation should be higher than the stated RDA; as much as 10 times more than that. This was suggested by Dr. Holick of University of Boston Medical Center.

If you want remedy to Vitamin D toxicity or Vitamin D deficiency with diseases such as fatigue, loss of bone density and depression, you should intake more than 200 to 400 IU of Vitamin D supplement. The higher the intake of Vitamin D supplements the better; up to the optimal recommendation of your doctor. It is always best to consult your doctor before you take any supplements.

You can intake as much as 2000 to 4000 IU of Vitamin D supplement. This level is found out to be very safe and much more effective compared to the stated RDA. Just take note that you should not exceed this level. Intake of 10,000 to 40,000 IU of Vitamin D will lead to Vitamin D toxicity. Instead of helping your body, it will lead to its deterioration.

Vitamin D is one of those vitamins that are hard to get from food alone. This vitamin is present in some fishes and eggs but you have to eat a lot of it before you achieve the RDA per day. This is the reason why Vitamin D supplements are essential.