Health Experiment (part II): How To Improve Your Vitamin D Levels When You Live at the Equator

Health Experiment (part II): How To Improve Your Vitamin D Levels When You Live at the Equator

Here is where I am coming from: I am regularly checking my blood values, for many years.

Usually, everything is in good order, or at least the measurement values are tolerable.

My latest annual check-up back in December 2023 revealed some changes, though. My blood values deteriorated after I had knee surgery after an accident: I stumbled in an unexpected water puddle in our staircase, and I ruptured my left quadriceps tendon. That accident left some traces in my general health. Not only was I literally set back to zero with my weights lifting results. I had to cancel my participation at the World Championship 2023. That was followed by a forced almost-no-walking period of 4 months. And this immobile lifestyle messed up my blood measurements. The story about that and about the healing that followed from December 2023 onwards will follow in another article once I am happy with the results.

My Vitamin D Levels Were Bad

During the 7-months long period since December 2023 until July 2024 I went through several blood tests, and I thought that I could try to improve my low Vitamin D levels.

I first tried to improve them by walking under the mid-day equator sun in Singapore. I thought that I could catch two birds with one stone: increase my daily walking distance and catch some UVB radiation.

The result was very clear: that does not work. Walking under the mid-day equator sun in Singapore does not significantly improve your Vitamin D levels. You can read up on my earlier experiment here:

Eating fatty fish is also not a viable solution, simply because you cannot eat so much fish: we are talking about 1.5 to 3kg of salmon or better more, per day!

This is why I switched to taking Vitamin D supplements, plus walking every day for 45 minutes under the equator sun.

Side information: I am also taking Magnesium and Vitamin K2 supplements, in order to prevent negative side effects of taking high doses of Vitamin D supplement.

Here Comes The Second Part of the Experiment

So I set up a program for doing so: I took 22,000 IUs of Vitamin D per day. Yes, you read right: 22,000 IUs per day. And I continued to walk every day at about 12:30, for about 45 minutes, without a hat, with naked arms and legs, wearing a T-shirt and shorts.

I did this for three (3) weeks, from 24 April 2024 until 14 May 2024. And after these 21 days, I measured my Vitamin D levels. They went up a lot, from 27 ng/ml to 76 ng/mL.

After seeing that success, I have reduced the intake of Vitamin D from 22,000 IUs per day to 14,000 IUs per day. I did this for about another two (2) months, from 14 May 2024 until 07 July 2024. And after these 7 weeks, I measured my Vitamin D levels again. They still went up, from 76 ng/ml to 88 ng/mL. Not bad.

Here are the individual measurement results:

And I have put a little graph together, for the more sophisticated reader:

Plan for the Coming Future

As I have achieved my goal to bring my Vitamin D levels into the higher areas of the “sufficient” region of 30-100 ng/ml Vitamin D in my blood, I am now switching to a lower dosage of Vitamin D of only 5,000 IU/day. My next measurement will be in around 6 months from now, in December 2024.


Walking outside to sufficiently increase your Vitamin D levels is not a viable solution. The same applies to eating fatty fish.

This is why I have started to take a Vitamin D-3 supplement, and I have taken up to 22,000 IUs per day. It was important to support that massive intake of Vitamin D by frequent measurements.

Once I saw the positive results of my efforts, I have adapted the intake of Vitamin D supplements accordingly.

I will report about the further result of my ongoing efforts in about 6 months’ time.


Martin “Vit D” Schweiger

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