What's Blocking Your D?

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The Pure TheraPro Team

The Pure TheraPro Education Team is comprised of researchers from diverse backgrounds including nutrition, functional medicine, fitness, supplement formulation & food science. All articles have been reviewed for content, accuracy, and compliance by a holistic integrative nutritionist certified by an accredited institution.
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Vitamin D is a fat-soluble vitamin that due to its steroidal structure, acts more like a hormone in the body than a vitamin. Vitamin D is responsible for supporting many bodily functions—healthy bones and teeth, immune function, neuro-muscular health, cellular regeneration, glucose metabolism, and more. How well you absorb vitamin D, however, is dependent on additional factors, so just supplementing with vitamin D may not be cutting it.

External factors such as getting optimal amounts of sunlight daily play a role in vitamin D’s absorption, so definitely get outside daily, if possible, for about 20-30 minutes of sun exposure without sunscreen. Vitamin D may also be obtained through food sources, such as fatty fish, eggs, beef liver, mushrooms, and fortified milks such as coconut and almond.

But getting enough sun and foods that contain vitamin D may not be enough. Even supplementing with high dose vitamin D may not raise your levels. Certain factors and conditions may interfere with vitamin D’s absorption rate and prohibit some people from increasing their vitamin D to optimal levels.

Here are some of those factors and conditions that may interfere with vitamin D’s absorption:

Dark Skin:

The more melanin your skin contains, the lower your ability to convert vitamin D from exposure to sunlight. Melanin "competes" for UVB with the substance in the skin that kick-starts the body's vitamin D production. If you have dark skin, you require more exposure to sunlight than lighter skinned people in order for your body to create vitamin D.

Magnesium Levels:

Magnesium helps activate the absorption and utility of vitamin D. This pairing also initiates the regulation of calcium and phosphate, other nutrients instrumental in supporting healthy bones. When you’re deficient in either vitamin D or magnesium, you have the potential of running into trouble—skeletal issues, autoimmune disease, metabolic issues, cardiovascular disease and more.

Even if you’re not magnesium deficient now, you increase your chances of becoming magnesium deficient if you’re supplementing with vitamin D without also supplementing with magnesium. Vitamin D requires magnesium for its own absorption, and it will tap into body stores of magnesium to use for its own absorption. Most people today have low magnesium levels simply because our soil and food lack the nutrient content it once had. Add vitamin D supplementation to the mix and this deficiency may develop into physical symptoms.

Be sure, however, to not take these two together. It is best to take your vitamin D in the morning with a meal that contains healthy fat to increase the absorption rate. Magnesium is recommended to be taken in the evening, with or without food.


Choose highly bioavailable forms of magnesium, such as magnesium malate and magnesium glycinate. These are also gentle on the stomach and don’t cause unpleasant side effects, such as diarrhea, loose stools and nutrient malabsorption.


Since sunscreen prevents sunburn by blocking UVB light, it lowers vitamin D levels. Toxins in sunscreens are endocrine disruptors which can affect delicate hormone levels.


Twenty to thirty minutes of natural sunlight daily without sunscreen provides enough UVB light for most people to receive the benefits of vitamin D conversion, although supplementation may still be needed to raise your levels or maintain optimal vitamin D levels throughout the year.

If you choose to wear sunscreen, be sure it's natural and free from toxins!


If you live far from the Equator, you receive less UVB light during winter. This means lower vitamin D levels, particularly during cold months with shorter, darker days. Winter weather requires bundling up in layers of clothing, making it harder to obtain the benefits of UVB light. This makes supplementing with vitamin D essential, particularly during winter.

Your Weight:

Obesity impacts your body’s ability to absorb and utilize vitamin D. Although vitamin D is fat soluble, extra pounds can result in low vitamin D levels, according to studies.  

Your Age:

Age reduces your ability to convert UVB light into vitamin D. This is important to know since vitamin D is vital for healthy aging. A deficiency of vitamin D is associated with many age-related conditions, such as osteoporosis, hip fractures, cardiovascular disease, arthritis and poor immune function.

Gut Health:

The absorption and utility of vitamin D is influenced by the health of your digestive tract. This includes gut mucosa, acid levels, pancreatic secretions, bile and the health of your intestines. Various gut illnesses can impact vitamin D absorption, such as Crohn’s, Celiac Disease, Leaky Gut Syndrome and ulcerative colitis.

Liver and Kidney Health:

When the liver is sluggish and doesn’t produce enough bile, vitamin D absorption may be affected due to incomplete vitamin D metabolism. Kidney disease can also lower vitamin D levels, particularly in end-stage renal dysfunction.


Pharmaceuticals that affect enzyme function can influence the conversion of vitamin D via the liver and kidneys and lower vitamin D levels as well as interfere with the body’s absorption of vitamin D. These include antibiotics, anti-fungal medications, anti-cancer drugs, HIV drugs and anti-inflammatory medications, such as corticosteroids.

Other Health Issues:

Any inflammatory condition can affect your body’s ability to properly convert UVB sunlight into vitamin D as well as utilize vitamin D properly. Autoimmune disease, cancer, heart disease and diabetes are all associated with low vitamin D levels. All the more reason to take a high quality vitamin D supplement. 


Our Vegan D3+K2 provides 3 in 1 support--Vitamin D3 along with two essential forms of K2 (MK-4 + MK-7).

Vitamin D helps the body absorb calcium, while Vitamin K2 helps the body ensure that calcium is properly utilized (i.e., that it is ending up in the bones and not in the heart and blood vessels). Vitamin K2 keeps calcium in bones and teeth and out of soft tissues. 

Our Vegan D3+K2 was ranked as one of the best vegan D3 K2 products on "Ode Magazine."


Our Vegan ADK provides 5-in-1 support and is a perfect supplement to help support immune function. It contains two forms of Micellized Vitamin A (palmitate and betacarotene), VEGAN Vitamin D3 along with two essential forms of K2 (MK-4 + MK-7).