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Vitamin D Guide: Benefits, Risks And Doses

Vitamin D is a fat-soluble vitamin that occurs in our body from the response to ultraviolet-B radiation from the sun, but not only. We also can increase it by consuming of certain food like fatty fish including tuna, mackerel and salmon but also beef liver or egg yolks.

Vitamin D has a major impact on bone formation and prevention of bone deformities such as rickets in children, and bone pain caused by a condition called osteomalacia in adults. Another role is to keep bones, teeth and muscles healthy by correct calcium absorption.

Unfortunately, we consider even over 77% of general population Vitamin D3 insufficient. That brings an abnormal risk of further health but also body functionality related issues. For decades scientists studied other potential problems with below average amount, and finally we can come to conclusions and real facts that became a significant change in health and wellness industry.

Benefits of vitamin D

We know vitamin D for its role in calcium and phosphorus absorption, but there are many other wonderful benefits rather than just the strong bones. Alongside obvious role, we can also state other important functions like protein synthesis, hormone synthesis, immune response and prevention from chronic diseases. In addition, the discovery of Vitamin D receptor (VDR) suggested a significant role in improvement of athletic performance such as:

– Strength and Power

– Speed and Cardiorespiratory System

– Reaction Time and Coordination

– Body Composition

Vitamin D deficiency risks

Because we hardly find vitamin D in the food sources and limited sun exposure depending on where you live you could face potential risks. Especially when your levels of Vitamin D are below 12 ng/mL you are on higher risks of:

Bone Density. It can contribute to osteoporosis and fractures (broken bones) because of weak calcium and other mineral absorption.

Diabetes. The β-cell in the pancreas that secretes insulin contains VDRs and the 1 alpha hydroxylase enzyme. Evidence shows that vitamin D treatment improves glucose tolerance and insulin resistance. Vitamin D deficiency leads to reduced insulin secretion.

Cancer. For the study, the researchers collected blood samples from 160 men and women with cancer and measured their levels of vitamin D. The five most common diagnoses were breast, prostate, lung, thyroid, and colorectal cancers.

Among people in the study, 42% had vitamin D insufficiency, defined as levels between 20 and 30 nanograms per milliliter (ng/mL) of blood. An additional 32% had vitamin D deficiency, with levels less than 20 ng/mL.

Libido. Vitamin D protects endothelial cells from oxidative stress, which results improved erections. Also, vitamin D deficiency we can link with a cardiovascular risk that can also affect sexual function; healthy levels of vitamin D may decrease this risk and benefit sexual health.

Guts. In recent studies appeared that deficiency of Vitamin D could have a direct impact on gut microbiome. The data suggests a vital role in modulating the microbiome, and deficiency may lead to inflammation and dysbiosis. As a result, you might face lower immunity system responses and potential further guts related issues.

How to check vitamin D3 levels

The most accurate way to check your current levels of vitamin d3 is the 25-hydroxy vitamin D (25(OH)D) blood test. It’s important to know exact amount in the body for the purpose of selecting the right strength of supplement, that is going to be appropriate to use within increasing vitamin D levels. For your reference, a level of 20 nanograms/milliliter to 50 ng/mL is adequate for healthy people. Aiming for the highest reference level. A level less than 12 ng/mL shows vitamin D deficiency.

What dose of vitamin D should you take

When you look for the vitamin D supplement, you are likely to find strengths provided in the International Unit (IU), which represents the strength and concentration within a single serving. Most common of the strengths of Vitamin D you will find as 1000, 2000, 5000 and even 10000 IU per serving. From my personal experience and years of advising customers, I always guide to check the actual level of Vitamin D first in the body before selecting the right strength.

Vitamin D3 Test

However, to make a quick assessment to choose the right dose, you can always ask the following questions to yourself:

  1. How often do I experience sun lights a week?
  2. Do I want to improve my performance or is it just for my personal health purpose?
  3. Am I struggle with joint pains?
  4. How often I eat food high in vitamin D?
  5. Do I struggle with my immunity system?
  6. Do I lack energy at a daily basis?

Quick Assessment

Using quick assessment can be helpful in selecting the right dose of vitamin D. For example, when you don’t experience a lot of sun, don’t consume regular food high in vitamin D, lacking energy and you want to improve your health, then you can start with recommended upper limit of 4000 IU. This is the upper limit by The Institute of Medicine.

You should continue dose of 4000 IU at least for 3-4 months before you notice a major improvement. This is because the raise of Vitamin D level takes a time to build in our system. Eventually after 4 months you can lower the dose down to 2000 IU and use it as a supportive dose to keep high and stable amounts.

If you also struggle with extra joint pains, weak immunity system and maybe other symptoms listed above then you can have a go on 10000 IU (Non-IOM Recommendations) to start with fast vitamin D rebuilding. Personally, I would recommend to take it for about 3 months following by drop to 5000 IU for another 2 months and eventually keep on 2000 IU to keep high and stable amounts.

When you are an athlete who has over 6/7 workout sessions a week, then a dose of 10000 IU should be mandatory to notice a major improvement on strength and performance results. Also by using a bigger amount, you will notice faster recovery and better VO2 MAX. You should follow this dose at least 3 months, followed by drop to 5000 for continuous daily use.

How to improve better Vitamin D absorption

Just using Vitamin D supplement in right dose for a specific amount of time might not be enough. There are certain tricks you can apply to get maximum benefit and improve your chances of getting the right level of Vitamin D in your body as fast as possible.

Have you ever heard of Vitamin K2? You can use a synergistic combination of Vitamin D3 and K2 together for enhanced benefit. They are both fat-soluble vitamins that play a central role in calcium metabolism. Vitamin K2 activates the protein, osteocalcin, which integrates calcium into bone while Vitamin D3 ensure that calcium absorbs easily. Without use of extra K2, the calcium may settle in your soft tissues, which associate with vascular calcification and kidney stones.

This is very important so the calcium can absorb but also be transported to your bones and teeth. Both nutrients are essential and beneficial to bone health and cardiovascular health, so stack them together!

Whenever you combine them both together make sure you choose the right form of K2. One of the best absorbable Vitamin K2 comes as MK-7 form. Also, you can find natural sources of Vitamin K2 in food like grass-fed hard cheese (76 mcg per serving), goose liver (369 mcg per serving) or even free-range egg yolk (32 mcg per serving).

When you combine them together make sure you use a correct ratio between Vitamin D3 and Vitamin K2, which normally is 5:1. Meaning, when you use 5000 IU of Vitamin D3, try to have around 100 mcg of Vitamin K2 as minimum. Research has shown also that we can use Vitamin K2 180 mcg per day for bone health, and 360 mcg daily for arterial calcifications without putting an enormous pressure on our health.


Considering over 77% of population has major Vitamin D deficiency, you could be in potential risks associated with having insufficient level. If you never looked into your current levels of Vitamin D3, we strongly advise you to check it with your local GP.

You can ask about (25(OH)D) blood test and see your current level of Vitamin D. This will allow to select the right strength of supplements to bring appropriate levels back to normal (a level of 40 nanograms/milliliter to 50 ng/mL).

Especially in winter time where we don’t experience a lot of sunlight, our level of Vitamin D can drastically drop and bring many health issues. To keep you in a healthy state and prevent from several health problems, I advise you to use the right strength of Vitamin D3 combined with Vitamin K2 (MK-7) form (5:1 ratio). Not only does vitamin D assist in growth and maintenance of the bone, but it also aids in regulation of electrolyte metabolism, protein synthesis, gene expression, and immune function so use it for your advantage.

If you still unsure how to use and select the right dose of Vitamin D, then let me know in the comments below. I will be more than happy to answer all your questions and settle Vitamin D supplementation plan for your maximum benefits. Is this article has been helpful? If yes, don’t forget to share remedy with your close friends and family.

Stronger Together, Coach Casper


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