…..I hope everyone has survived the earthquake and Irene; my home lost power for five days, and it was not easy without the lights. Today we will finish up our discussion of vitamin D.
…..Vitamin D2 and D3 are changed in the liver to 25-Hydroxyvitamin D. That is the last time you will see that tough word since I will refer to it as 25(OH)D. This is what is measured in the blood, and it determines if we need to have extra vitamin supplementation. Vitamin D insufficiency is usually defined as a serum 25(OH)D level of 30 to 32 ng/ml.
…..In regard to calcium absorption, most studies suggest that with a 25(OH)D level of at least 20 ng/ml, there will be maximum absorption.
…..The daily recommendation for vitamin D is 600 IU for healthy non-pregnant women under 70 years of age and 800 IU for women older than 70 years.
…..Extra vitamin D should be added if the level is below 30 ng/ml. As a general rule of thumb, an extra 1000 IU per day of vitamin D3 will increase the 25(OH)D levels by 6-10 ng/ml. The levels should be checked after a three month trial.
…..Lastly, some studies point to problems if the 25(OH)D levels are greater than 50 ng/ml, so always check levels after adding extra vitamin D.