It seems that numbers have become a pervasive part of our lives. Think about it for a moment. How many times each day do we deal with numbers? Our social security number, phone number, address, age, the cost of gasoline, even our IQ's and credit scores. The list goes on and on. And from a medical perspective, what about your blood pressure, or cholesterol level, or your weight and vision?

Unfortunately, there are two more numbers that I need to bring to your attention. They're both important to your health, and you're probably not familiar with them, at least not yet.

The first is your vitamin D level. Now, most of us are familiar with this vitamin. It's been used to fortify milk for several decades, and maybe you remember from your grammar school days that its deficiency causes rickets.

We don't see much rickets anymore, but we are learning more about the importance of this nutrient. We've known that it has a significant role in how we handle calcium and with bone metabolism. Low levels of this vitamin can contribute to osteoporosis and fractures, especially in the elderly. But recently we are beginning to appreciate how this vitamin works in other important areas. For instance, low levels of vitamin D can result in an increased risk of heart disease, as much as 80% when levels are significantly low. And there appears to be a connection between this vitamin and your immune system. Low levels are associated with a decreased ability to fight certain infections.

Recent studies have suggested that there may also be an association with vitamin D deficiency and multiple sclerosis, certain autoimmune diseases, type 1 diabetes, cancer, and high blood pressure. It needs to be stated that this deficiency does not cause these diseases, but may have some undefined role in their development.

Unfortunately, most of our diets are deficient in this vitamin. With the exception of fatty fish oils, most of what we eat contains very little vitamin D. That's why it was added to milk, hoping that would help insure adequate intakes. And levels can also be increased by spending some time in the sun. A chemical in our skin is converted to active vitamin D by the action of specific ultraviolet wavelengths. It doesn't take much time to accomplish this, usually about 30 minutes a day, depending on the time of year.

So, what are we to do with this information? I mentioned another number, and that would be the level of vitamin D in your blood. This is a simple test, and will quickly tell you where you stand. If the level is low, it can usually be quickly corrected. In the meantime, a reasonable approach is to take a supplement that contains at least 400 units a day, 800 if you're over 60. However, this is one of the few vitamins that can cause problems if taken in excess, so you don't need to exceed that amount unless directed by your physician.

The other number you need to be aware of is your GFR. I know this sounds like something you'd add to your gasoline, but it actually stands for "glomerular filtration rate". Basically it's a measure of how well your kidneys are functioning. This is another simple blood test, and most laboratories are performing it as part of a routine blood chemistry analysis.

So how could this number help you? We've all heard about the "silent killer", high blood pressure. Well, the onset of kidney disease can also be insidious and not clinically apparent until you're way down that road. Sometimes, it may be too late to do anything about it. The earlier you become aware of a potential problem with your kidneys, the earlier you can begin doing something about it. Ask your doctor if she is checking this on a regular basis.

That's it. Two more numbers we're going to have to deal with. But don't get me wrong. Numbers are important to us. But for 7's sake, 1 thing is 4 cer-10: you don't want 2 fix-8 on this thing. This is not a be-9 habit, and can off-10 lead 2 head-8's, addiction, 4head rashes, and all kinds of 6ness.