Vitamin D – How Much Do I Need?
The topic of vitamin supplementation is an important one, and of all the essential vitamins, Vitamin D deserves attention. But first a little bit about Vitamin D. Despite its name, Vitamin D is not a vitamin in the usual sense, but is classified as a “seco-steroid.”
Generally vitamins serve to help push forward certain biochemical reactions in the body, to make them run efficiently. That way the final product of the reaction is always available. This would be similar to an assembly line which fastens a door to a car. If the door fastener is having problems, then the production of the car slows down.
Where Vitamin D differs is that it is not used to regulate a specific chemical reaction, but rather works more like a hormone. As a “seco-steroid,” its actions are within the nucleus of the cell where the DNA genetic material resides. There, it forms a complex, with other hormones. And together, this complex regulates the activities of over 900 different genes. As a result it has quite a few activities.
We are most familiar with Vitamin D and its role with managing calcium, as it is usually supplemented in dairy products. However it is also active in things we don’t think about, like our immune system, heart and blood vessel health, controlling cell growth, meaning problems here can contribute to cancer. To complicate matters, some people may have genetic variations in their Vitamin D complexes in which low Vitamin D levels can magnify health problems. This has particularly been noted in the area of cancer. So having adequate stores of Vitamin D is important for everyone, but for some more than others. But equally important to know, excess Vitamin D can also create health problems.
How much Vitamin D is needed?
Generally Vitamin D is created beginning with sunlight on the skin. However in our modern world, with most working indoors, we are exposed to less sunlight than before. As a result, supplementation may be necessary. Current US RDA for supplementation is 600 IU (International Units) for adults and 800 IU for elderly over 70 years old. Good natural food sources for Vitamin D include fish, eggs, and mushrooms. As noted earlier, some foods are fortified with Vitamin D.
So despite eating those foods, getting plenty of sunlight, or taking supplements, why do I still have low Vitamin D levels?
There may be reasons for this as well. One may be difficulty with certain gastrointestinal conditions. But if there are no obvious gastrointestinal problems, one area that was recently studied was that of chemicals and pollutants called endocrine disruptors. There are certain chemicals involved with plastics, pesticides, which are associated with low Vitamin D levels. Another common condition is that of excessive uric acid, which is highly inflammatory, being accompanied with low levels as well. It might be worth considering that inflammation creates excessive Vitamin D consumption, given its contribution to the immune system. Because ongoing inflammation is never good, this would need to be separately addressed.
So if I’m supplementing but my levels are still low, what next?
As noted excessive Vitamin D can create problems. So a person may need to be careful if using a higher dose than the recommended allowance. The good news is that levels can be easily checked by your doctor until you find an appropriate dose.
