Product Reviews By Damon Miller Vitamin D. An essential nutrient we all need. However, there is much disagreement among doctors as to how much Vitamin D needs to be taken as a supplement. Physicians, who often prescribe and recommend vitamin D2, have concerns because too much vitamin D2 can definitely be toxic, and harmful to your liver. Integrative practitioners, and people who understand supplements and natural medicine, would never use Vitamin D2 and instead routinely recommend Vitamin D3. If you can find a case report of someone damaged by vitamin D3 I’d like to see it. The only one I can find is a case of someone who had mental health issues and was eating a bottle of D3 a day. Thankfully, how much vitamin D you need is not a theoretical discussion. You start with a dose you are comfortable with, and after six weeks on that dose, check your blood level and adjust your dose as needed. If you don’t have insurance that will pay for this, the test (for 25-hydroxy cholecalciferol) costs about $20. It’s a very effective way to find the dose that’s best for you. I have seen clients where their physician ordered a Vitamin D level, and then found their level to be low (which is the norm for most of the people in the United States). They then recommended that the person take Vitamin D for a few days to get their levels back up and then discouraged them from taking it on a regular basis. Not surprisingly when they check their Vitamin D level again six months later it’s low. This cycle can go on for years, and when it does you loose out. Why would you worry about your Vitamin D level? Well if for no other reason than to prevent colds and flu. There is very impressive data on the relationship between the levels of Vitamin D in your blood and your likelihood of getting the flu. You could almost say that maintaining a healthy Vitamin D level (I recommend you stay at the high end of the reference range for your lab) gives you virtually a zero chance of getting colds or flu during flu season. The amount of Vitamin D most people need to maintain a healthy blood level is about 5,000 to 10,000 international units (I.U.) per day. Some studies estimate this is what we normally would generate, if we followed the same lifestyle of our ancestors. In this I mean spending a majority of the time outside, not wearing hats, sunscreen or clothing designed to block the sun’s rays. It is those rays that normally convert cholesterol into Vitamin D. The production of 5,000 to 10,000 units per day is normal and physiologic, meaning this is what we would do naturally if we didn’t live in the modern age. Interestingly, this number is far greater than what is recommended. I was just referred to two studies in the journal Nutrients from 2014 (Nutrients, 2014, 6, 4472-4475) (Click HERE for article) which found that the Institute of Medicine, the group charged with developing recommendations for nutritional support from food and supplements, has under estimated the amount of Vitamin D we need daily. How did the Institute of Medicine and the US National Academy of Sciences underestimate our need for Vitamin D? The basis for the recommendation comes from studying people who appear to be healthy, determining what the average vitamin D level is in “normal” people and using this as a recommendation, after you have determined how much vitamin D they are getting from food and supplements. Looking deeper we find some problems with the research. First, the studies that the recommendations were based on were conducted in the winter when people’s vitamin D levels are normally lower. Secondly, they ignored a large body of research suggesting that the majority of people in the United States have an inadequate level of vitamin D all year long. This is due to a number of factors, not the least of which comes from modern food not having the level of nutrients we might expect it to have. As a result we operate already with a reduced level in our systems, so that even “normal” is low. So, following their recommendations will leave you deficient in Vitamin D. I recommend that you do not follow the recommendations in this case. You don’t have to rely on theoretical numbers. Start with a reasonable dose of Vitamin D has a supplement, maybe 5,000 international units per day. Take this for 6 to 8 weeks. Then do a blood test and see if you’re at a good level. Adjust how much vitamin D you take to keep your serum level in the upper limits of normal. Some people may need less in the summer time. Some people may need 10,000 international units per day to maintain a healthy blood level. I have clients who need to take 50,000 international units per day to maintain a healthy blood level. Base your level of supplementation on what your body needs, as determined by an inexpensive blood test. Your body will let you know, if you listen to it. And remember, if you use vitamin D3, the risks are virtually zero. Just try it. If you do you might receive exactly what you need to stay healthy and strong all year round. To Your Health.