![logo](https://drhoffman.com/wp-content/themes/drhoffman/images/logo.gif)
![Plus 1](https://drhoffman.com/wp-content/themes/drhoffman/images/small-logo.gif)
Q: I’m a healthy 61 year old female with an ongoing vitamin D deficiency. My doctor has given me 25,000 IU vitamin D per week over a 10-week period a few times over the last 18 months and my levels continue to remain low (in the 20s). What’s going on here?
A: Based on your information, there are two reasons why your levels may continue to be low.
First, taking 25,000 IU vitamin D weekly only measures up to about 3,570 IU per day. That’s not enough to help increase your serum levels. You would need at least 5,000 IU daily to make an impact. Some years ago, a study of Nebraskan men found that about 7,000 IU vitamin D3 was needed daily just to maintain serum levels over the winter.
Second, if your doctor is giving you vitamin D, it is likely a prescription for vitamin D2 (ergocalciferol) which is inferior to vitamin D3 (cholecalciferol) in optimizing your vitamin D status.
As a matter of fact, vitamin D2, which is plant-based, shouldn’t be used in fortification or supplementation according to an article on the American Journal of Clinical Nutrition. Essentially, vitamin D2 has a diminished ability to bind its metabolites to vitamin D binding protein in plasma. Hence, its inefficacy to raise 25-hydroxyvitamin D levels (the standard blood test to measure vitamin D).
Think about it this way: Sunshine and fish consumption provide D3, not D2. That’s the version of vitamin D we’re supposed to get.
There may be other reasons your vitamin D status remains low. You can read about it here.
To your health!
Though we think of declining estrogen as the hallmark of menopause, it's actually common for…
Up to 12 percent of Americans have ulcers at some point in life. Peptic ulcers…
Gallbladder disease is a modern illness. An estimated 20 million Americans have gallbladder disease. The…
I’m a veteran of the Diet Wars. Back in the 80s, when the ultra-low-carb Atkins…
Q: I’ve read that twenty minutes of sun exposure will give us 10,000 to 20,000 IV…
I couldn’t resist. Rather than leave these candidates for “Breakthrough treatments that we don’t really need” on…
Leyla Weighs In: Exercise as a Drug-Free Longevity Pill
Our virtual voicemail is open 24/7, so there's no need to wait to submit your questions for Dr. Hoffman. Leave a message, and you may hear your question featured on the Intelligent Medicine radio program!