The Dangers of Vitamin D Deficiency

Vitamin D Deficiency. While you can get vitamin D through food or supplements, exposure to the sun is most people’s main source of vitamin D.

It used to be thought that vitamin D’s primary impact was confined to the skeleton. Everyone knew that getting enough vitamin D was important for preventing rickets and other bone diseases, but they thought that was all there was to it. Now researchers have found that vitamin D impacts a wide variety of other body systems and functions as well.

Unfortunately, it is estimated that the vast majority of people (90 percent by some estimates!) do not get enough vitamin D.

Why is vitamin D deficiency now so common?

There are a number of reasons why vitamin D deficiency has become so widespread. These include:

  • Increased use of sunscreen
  • Decreased amount of time that people spend outdoors
  • Reduced intake of vitamin D in food
  • The use of high-dose pharmaceutical drugs that inhibit the body’s ability to properly absorb vitamin D

What does vitamin D do for my healthy cells?

Researchers have found that vitamin D:

  • Regulates the enzymes in your brain that help with nerve growth, neurotransmitter production and synaptic density. These are all things that are essential for brain health.
  • Helps maintain intracellular calcium and phosphorus levels.
  • Protects your nervous tissue from oxidative stress.
  • Helps control your immune system response.
  • And more.

Why is vitamin D important for fighting cancer?

There have been many observational studies and two randomized controlled trials that found that vitamin D reduces the risk of about 15 types of cancer. The evidence of this is strongest for colorectal and breast cancer.

One of the reasons why vitamin D reduces cancer risk has to do with how it interacts with other substances in your body. Your body makes a protein called GcMAF that is critical for a healthy immune response; GcMAF can actually aide in killing off tumors entirely. GcMAF is produced by modification of a vitamin D-binding protein, which is naturally promoted by lymphocytes, a type of white blood cell found in your lymphatic system. But when your body is deficient in vitamin D it’s deficient in GcMAF as well. This means that you’re not getting the advantage of the GcMAF’s cancer cell fighting abilities. Vitamin D3 deficiency is one of the most common factors that contributes to cancer cells’ ability to flourish.

What are some other possible effects of vitamin D deficiency?

In addition to increased cancer risk, researchers have found that Vitamin D deficiency is also associated with:

  • Cognitive impairment and dementia. Although the studies are not conclusive, it appears that low levels of the active form of vitamin D are associated with loss of brain development and neuroprotection. Vitamin D deficiency causes a variety of problems that reduce the ability of brain cells to survive.
  • Infectious diseases including bacterial (pneumonia, sepsis) and viral (accurate respiratory tract infections, influenza) diseases. In fact, some studies have found that vitamin D may be as effective as vaccines in reducing the risk of influenza.
  • Diseases of the central nervous system including schizophrenia and multiple sclerosis, especially when the deficiency takes place during neonatal development.


In my personal journey, vitamin D is a must have in my supplement cabinet. I consider it one of my top supplements for my personal line of defense. When I was first diagnosed it was pointed out to me my deficiency in vitamin D level which was corrected right away. I can honestly say I felt the difference. Especially, when I went back on it after I stopped taking it for a while during a period in my healing journey. What about you? Have you tried vitamin D? Is it one of your top supplements to take? How many units do you take? Have you felt any different? Remember, I always welcome your feedback and I appreciate you sharing your experiences with me. Thank you for reading!

Click Here to try the vitamin D that I prefer!


  1. Nita Riggs Samuels on September 21, 2017 at 10:32 am

    Thanks for your article Karen…I’m working on building my vitamin D back up again. I take about 5,000 iu along with vitamin k2…I learned through Dr. Mercola that K2 works hand in hand with vitamin D to get the calcium to where it should be. I also found out that maintaining vitamin D levels can be a protective barrier against seizure disorders. I need to get more sun though…no excuse since I live right in Los Angeles. When I relax in the sun, it feels peaceful and calming. Thanks again Karen for this information.

    • Karen Berrios on September 25, 2017 at 2:15 pm

      That’s great info Nita! I really like Dr Mercola, he’s full of information and experience. Thank you so much for sharing what you’ve learned and for reading my article. 🙂

  2. Kassia on September 21, 2017 at 6:32 pm

    I have hashimoto and my Vitamin D,25-OH,TOTAL,IA (30-100 ng/mL) is at 21 and my dr told me that they refuse to put me on vitamin D because if I would just lose weight then it would straighten out. I’m 5’3″ and 170 and I barely eat as it is so I’m not sure what else to do. So they just want me to take contrave or saxenda to lose the weight first.

    • Karen Berrios on September 25, 2017 at 2:27 pm

      Hi Kassia,

      I’m so sorry to hear you are going through this. I’m not a doctor so I can’t offer you any medical advice but I can share my experience and so I would recommend to seek additional medical opinions. I work with a Functional Medice DR… (My Dr. Erik Lundquist) and he’s just the best. He combines the best of both worlds to help his patients. I so appreciate this option since it empowers the patient with additional options, education and a healthier lifestyle approach. Sending you lots of love and healing… God bless princess 🙂

  3. Susan on October 29, 2017 at 3:54 pm

    My daughter has papillary thyroid cancer and she’s 22. Her doctor put her on 10,000 IU of Vitamin D. He wants her levels to be around 70 -she’s at 48.7. Unfortunately, the vitamin D she has forgotten to take for the last 2 – 3months since she has to refrigerate it!! I’m wondering if we can bump her dosage to 20000 IU per day to catch up!! What levels does your doctor want you at?

    • Karen Berrios on November 5, 2017 at 3:41 pm

      Hello Susan,

      I’m sorry about your daughter but I’m hopeful things will unfold favoraby for her. I’m not a medical doctor so I could not provide you with any advice. However I can share my experiences here. My doctor always tells me he wants to see my vit D levels in the 70’s. I currently take 8000 units but when it was low I was taking a higher dose. It will be best to ask her doctor to see what is the best dosage for her for where she’s at right now. Thank you for sharing…Blessings 🙂

  4. Maria Hall on May 1, 2018 at 12:31 pm

    Thank you for the article, Karen. Interestingly enough, my son who was just diagnosed with Barrett’s Esophagus has extremely low Vitamin d level. He too began taking 5,000IU daily along with K2.

    • Karen Berrios on May 7, 2018 at 4:07 pm

      Hello Susan,

      I’m sorry about your son but I’m hopeful things will unfold favorably for him. I hope that this information may be helpful for your particular case. Thank you for sharing…Blessings!

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