This is the first time I have used a website address as the title of an article. It seems appropriate, because the article is about that website. The Vitamin D Wiki Website has over 15,500 pages of studies about vitamin D, divided among more than 500 categories.
Take a look at it, then come back.
Vitamin D is the most researched vitamin in PubMed, the US National Library of Medicine website, according to my search before writing this. Here is the number of mentions of a few vitamins:
- Vitamin D: 108,558
- Vitamin C: 79,136
- Vitamin A: 60,989
- Vitamin B12: 31,892
- Aspirin: 77,085 (Okay, aspirin is not a vitamin, but I was curious.)
- So, you name a health problem, and you can find research support on the Vitamin D Wiki site or on PubMed for maintaining optimal vitamin D levels. This is why I recommend vitamin D according to blood levels, rather than according to symptoms. Almost everyone needs more.
WHAT IS AN OPTIMAL LEVEL OF VITAMIN D?
Certainly not the bottom of the “normal” range.
There are two different ranges for vitamin D. One is numerical, counting how many molecules of the vitamin are in a liter of blood. The normal range is 75 nmol/L to 250 nmol/L. The second is based on the weight of the molecules, 30 ng/ml up to 100 nmol/ml. Notice that if you need to convert one range to the other, in order to understand something you’ve read, multiply or divide by 2.5.
Ideally, the level for prevention of cancer and many other diseases starts close to midrange and is completely safe up to the top of the range. So, I’d say you should get your blood level at least 50 ng/ml or 125 nmol/L.
Don’t pay much attention to the warnings that too much vitamin D is poisonous and causes calcification. That is true only at very high blood levels, and you won’t get there unless you start swallowing whole bottles of pills. The danger of vitamin D is not having enough. If you are worried about this, add vitamin K2 and magnesium. Get advice about your individual situation.
DOSE
Just about anyone can take 5,000 IU (International Units) of vitamin D per day for a long time, without getting an overdose. However, it is certainly best to get tested before starting, and then every six months to a year. If your blood level is very low, you may need to start with 10,000 IU or even more. I’ve had patients with less than 10 ng/ml.
Although 10,000 sounds like a high number, here’s a fun calculation:
- To get the weight of vitamin D in your supplement, you divide the IU by 40. Therefore,
- Each 10,000 IU dose of vitamin D is 250 micrograms of the vitamin.
- I asked ChatGPT to figure out how many doses of pure vitamin D would fit into a teaspoon.
- The answer is about 19,000.
- Dividing that by 365 days in a year, it turns out that:
At a “high” dose of 10,000 IU per day, it would take you 52 years to take one teaspoon full of vitamin D!
How amazing is it that such a tiny amount of this vitamin is so incredibly important to the proper functioning of your body!
CONCLUSION
The dosage different people need to raise or maintain their vitamin D levels varies widely. For some, 5,000 IU for a few months is enough. For others, even 10,000 will do it very slowly. Besides baseline levels, other factors are exposure to sunlight, skin color, body-fat percentage and genetic factors. Some people need magnesium to raise their levels.
Therefore, it is important to retest after taking vitamin D supplementation for a few months. Do not supplement for at least three days before getting a test, so as to measure the balance, rather than what is left over from your last dose.
