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Dana Reed
"An insufficient or deficient level of vitamin D carries an elevated risk of numerous chronic health issues."


Vitamin D: The Super Nutrient
Frequently Asked Questions

During the past few years, understanding of the actions of vitamin D and the amount needed to maintain healthy levels has increased dramatically.

Why is vitamin D important to my health?
Vitamin D plays a role in calcium metabolism, strength of bone and cartilage, teeth and gum health, cardiovascular function, glucose metabolism, immune function, cognitive function, muscular strength, and adrenal function. Thus, an insufficient or deficient level of vitamin D carries an elevated risk of numerous chronic health conditions including bone loss, arthritis, periodontal disease, inflammatory conditions, autoimmune diseases, cancer risk, muscle weakness and pain, and mood disorders. Based on my experience and those of other practitioners, repletion of vitamin D to optimal levels can make a real difference in your quality of life.

Why is it necessary to test my vitamin D level?
Testing will help us to determine whether or not you need to supplement with vitamin D, and if so, how much supplemental vitamin D you need. You should be re-tested on a regular basis as your needs will change as you supplement. They may also vary based on season and the amount of time you spend in the sun. For most people, late summer testing yields the highest levels, as stored vitamin D is activated (and depleted) during the winter months.

Exactly what test should I ask my doctor for?
Serum 25-OH D. This test is a simple blood test done by Quest and many other Labs and is covered by most insurance plans.

If my results are within the lab reference range, does this mean my levels are adequate?
Based on the most current information, the following are reference ranges for 25-OH vitamin D that I am using when designing supplement programs for my patients.

10-60 ng/mL = Laboratory reference range (Quest)
Below 20 ng/mL = Clinical deficiency (Quest)
20-32 ng/mL = Insufficiency
32-40 ng/mL = Marginal sufficiency
40-60 ng/mL = Optimal

If my tests show that my levels are less than optimal, how much vitamin D do I need to get from my food and supplements? Can I correct my levels with diet alone? How do I know if I also need a supplement, which one should I take, and how much?
Although some vitamin D is found in fortified foods (e.g. milk, cereal, orange juice), it is difficult to correct a deficiency or insufficiency or even to maintain optimal levels with diet alone. According to most experts, the current RDA of 200-600 IUs for 20-75 year olds respectively is inadequate to maintain vitamin D homeostasis during winter months. Thus, a good quality vitamin D-3 supplement is required for most people, especially during winter months and for those who spend little time in the sun.

I will recommend a vitamin D supplement for you and outline the proper dosing schedule based on your test results, how much time you spend in the sun, your diet, and other lifestyle factors.

How much vitamin D is too much and what are the consequences of over-consuming?
Vitamin D is a hormone-like substance that is stored in your body. Just as insufficient levels can increase your risk of chronic health issues, so can too much. This is why it is recommended that you get tested. If your serum 25 OH-D levels are 100 ng/mL or greater, if you have hyperparathyroidism or sarcoidosis, you should not take vitamin D supplements.

How often should I re-test?
It is normally a good idea to test every 3 to 12 months depending on your required level of supplementation.