Quick Summary:
- 86% of men are deficient: Most men have suboptimal vitamin D levels and don’t know it — including Dr. Sam himself until a blood test revealed it years ago.
- Low vitamin D tanks testosterone: There is a direct correlation between low vitamin D and low testosterone, low libido, fatigue, joint aches, and poor mood.
- Vitamin D works like a steroid hormone: It functions similarly to testosterone in the body — which is exactly why deficiency hits men so hard.
- Sun alone is rarely enough: You need 45 minutes of high-noon sun on most of your body daily. Most men — especially those over 40, overweight, or with darker skin — simply can’t get this consistently.
- Take D3, not D2: Always supplement with Vitamin D3 in a plant-based, microencapsulated form — not cheap gel caplets that absorb poorly and go rancid.
- Always pair D3 with K2: Vitamin K2 directs calcium into bones and away from arteries. Taking D3 without K2 long-term can cause arterial plaque buildup.
- Perfect Vitamin D&K does both: Dr. Sam has used Perfect Vitamin D&K for years — the right dose of D3 and K2 together in one plant-based, microencapsulated formula that doesn’t go rancid.
Here is a shocking statistic.
Up to 86% of men have suboptimal vitamin d levels.
And there is a direct correlation between low levels and low testosterone. In fact, almost every guy I tested was deficient. Here’s what the research shows on does vitamin D3 increase testosterone.
Yes, this includes even me a few years ago. This is why it is such an important topic to me.
Problems such as low testosterone, lowered libido, feeling tired, muscle and joint aches, not feeling as happy, especially during the winter, and getting sick more often — consequently, these are all symptoms of low levels.
Why Vitamin D Works Like a Steroid Hormone
Most people don’t know that vitamin d actually functions as a steroid hormone.
In fact, just like testosterone. That is exactly why it is so powerful.
How to Get Adequate Vitamin D Levels
There are two places to get enough of it. However, most men are falling short on both.
1. The Sun
First, the most important source is the sun. You need about 45 minutes daily around high noon with the sun hitting most of your body.
Certainly, not during winter on just your hand or face — that is simply not enough.
Furthermore, if you have darker skin, are overweight, or are over the age of 40, your body has a harder time converting sunlight properly. As a result, supplementation becomes essential for most men.
2. Vitamin D3 Supplements
Second, you need to supplement. Specifically, take Vitamin D3 — not D2 and not generic.
In addition, avoid the cheap gel caplets.
For instance, they are not absorbed as well and they go rancid quickly.
Instead, take a plant-based, microencapsulated capsule form.
As a result, it has the highest potency and does not go rancid.
Why Vitamin D Must Be Paired With K2
When you supplement, you should always take it together with Vitamin K2.
This is because K2 helps direct it into your bones where it belongs — rather than causing plaque buildup in your arteries.
Therefore, never take one without the other. You can also read more about how hormones affect men’s health and natural ways to boost testosterone on this site.
The Right Vitamin D Dosage
I suggest starting with the following, taken daily with food in the morning:
- 5,000 IU (125 mcg) of Vitamin D3
- 50–100 mcg of Vitamin K2
Personally, I take double this dose because my levels required it. Nevertheless, start here first. Then recheck your blood work after 90 days and adjust accordingly.
The Vitamin D Supplement I Use and Recommend
The product I have been using for years is Perfect Vitamin D&K.
It has the right dose, it is plant-based, microencapsulated, and does not go rancid.
Make sure you are taking both together daily with food.
Additionally, get your blood levels checked — most men are deficient and don’t even know it is hurting their testosterone and overall health.
Important "Increase Your Vitamin D+K" Shortcut
There are literally dozens of health benefits when improving your Vitamin D levels ... However, there are two big problems:
- Problem #1: About 93% of people are deficient or sub-optimal levels of Vitamin D
- Problem #2: Primary way to get Vit D is from 45-60 min of daily sunlight daily (your entire body, not just face or hands)
This is why its best to take a daily supplement to ensure you have healthy & optimal Vit D levels.
And make sure you take Vit D3 with K2 to ensure proper absorption and calcium metabolism for brain & heart health.
- Pilz S, et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res. 2011;43(3):223–225. PubMed
- Farhan M, et al. Association Between Vitamin D Deficiency and Testosterone Levels in Adult Males: A Systematic Review. PMC. 2023. PMC
- Nimptsch K, et al. Association between plasma 25-OH vitamin d and testosterone levels in men. Clin Endocrinol. 2012;77(1):106–112. PubMed
- Chen C, et al. Causal Link Between Vitamin D and Total Testosterone in Men: A Mendelian Randomization Analysis. J Clin Endocrinol Metab. 2019;104(8):3148–3156. PubMed
- Forrest KY, Stuhldreher WL. Prevalence and correlates of vitamin d deficiency in US adults. Nutr Res. 2011;31(1):48–54. PubMed