Many years ago, I was part of a group of doctors who trumpeted the need for taking vitamin D. At that time, no one was taking supplemental D. Most people got it from the sun and from their fortified milk.
We also made waves when we said the starting dose was 5,000 IU daily. Most so-called experts recommend a paltry 400-800 IU. That’s only 10-20 micrograms.
Today, vitamin D is one of the most popular supplements on the market. Even people who are skeptical of supplements take vitamin D.
But it’s time to make waves again. That’s because most people are still not taking enough vitamin D. Even if you’re taking 5,000 IU daily, you still might be deficient.
A recent study found that 97.5% of people need to take 8,895 IU of vitamin D daily just to avoid a deficiency.
In other words, nearly all adults should be taking at least 9,000 IU per day. And the bigger you are, the more you need to take to achieve that level. Many of us need to be taking 10,000 IU daily. That’s how much I take.
What’s more, if you’re overweight, you need to take 2 to 3 times as much vitamin D as a lean person. It takes that much to reach optimal levels.
Optimal levels are 75 nmol/L or above. This was proven in a recent meta-study analyzing 47 years’ worth of data. The conclusion: Less than 75 nmol/L may be too low for safety. In fact, it could significantly increase your risk for serious health issues.
Another study found that if you want to avoid all health problems caused by vitamin D deficiency, you should ideally keep your levels over 100 nmol/L.
To achieve that level in the winter may require doses even higher than 10,000 IU.
It’s Not Just Northerners Who Are Deficient
A study on lifeguards in California found that while most were in an acceptable range, some of them were deficient. These are young people who spend most of the day in direct sunlight. So for any of them to be deficient shows you just how hard it is to get enough vitamin D from the sun.
Unless you’re in the sun all day long, you need to be taking vitamin D. A lot of vitamin D! And make sure you’re taking vitamin D3, as the body doesn’t absorb vitamin D2 well.
But there’s something else you need to know about vitamin D. It has to be activated to work right. Your kidneys are responsible for taking supplemental D and converting it to the active form. And your kidneys need four other supplements to make the conversion: niacin, zinc, selenium, and magnesium.
So make sure you’re taking a high-quality multivitamin along with your vitamin D to get the most out of it.
How Much Vitamin D Is Too Much?
Every time I recommend taking 10,000 IU of vitamin D, the patient always asks, “Isn’t that toxic?”
The answer is no, not even close. One study gave 100,000 IU to participants and found no side effects at all. Other studies have found that IV, injection, and oral application of 300,000 IU is completely safe – no adverse effects whatsoever.
So is taking 10,000 IU or more safe? Absolutely. In fact, it’s what 97.5% of the population should be taking through the winter months. Some people need to take even more.
The next time you get bloodwork done, make sure your doctor is testing for vitamin D levels. In the meantime, you can feel perfectly safe taking 10,000 IU per day.