The Most Important “Vitamin” You Need, and Why

by | May 26, 2022 | Resources

Did you know that around 40% of the US population is deficient in Vitamin D?

Most of the population is aware of Vitamin D as the vitamin that comes from the sun or eating fatty fish. Although these things are true, Vitamin D plays a much more important role in our bodies than most realize. 

Vitamin D is an essential nutrient that helps the body absorb calcium and phosphorus. Although Vitamin D is often thought of as a dietary factor, it is a prohormone. A prohormone is a hormone that is produced in one part of the body and then transported to another part of the body where it has an effect. The term “prohormone” comes from the Greek word’s “pro” and “hormone”, which literally mean “before hormone”. Prohormones are precursors to hormones and are not themselves active hormones. However, they can be converted into active hormones by enzymes in the body. Some common prohormones include testosterone, estrogen, and progesterone.

This hormone, called calcitriol, plays an important role in regulating calcium levels in the blood. Calcitriol helps the body absorb calcium from food and aids in calcium reabsorption in the kidneys. Calcitriol is also involved in bone remodeling, making it essential for bone health. While vitamin D is essential for bone health, it is also important for many other processes in the body, including immune function, cell growth, and reducing inflammation.

Vitamin D also plays an important role in gut health. Studies have shown that vitamin D deficiency is linked to several gastrointestinal disorders, such as inflammatory bowel disease and irritable bowel syndrome. Furthermore, vitamin D plays a role in developing and maintaining the intestinal barrier, which helps protect the gut from harmful bacteria and toxins. Vitamin D is also critical for those struggling with autoimmune diseases. 

Most people get their vitamin D from exposure to sunlight. However, this isn’t always possible, especially during winter months or for people who work indoors. Fortunately, there are other sources of vitamin D, including certain foods and supplements. By understanding its importance and how to get enough vitamin D, you can maintain optimal health.

Some foods that are strong in Vitamin D include salmon, fatty fish, and egg yolk. If there is a single supplement that you should take, it would be Vitamin D3/K2. However, even with intaking these supplements or eating high amounts of Vitamin D, these levels should be checked every 3 months.

To check on your vitamin D levels or if you’re concerned, you’re deficient, please reach out to me! I’d love to get to know you better during a FREE Discovery Call. You can book your Discovery Call today at

Forrest KY, Stuhldreher WL. Prevalence and correlates of vitamin D deficiency in US adults. Nutr Res. 2011 Jan;31(1):48-54. doi: 10.1016/j.nutres.2010.12.001. PMID: 21310306.

Sassi F, Tamone C, D’Amelio P. Vitamin D: Nutrient, Hormone, and Immunomodulator. Nutrients. 2018 Nov 3;10(11):1656. doi: 10.3390/nu10111656. PMID: 30400332; PMCID: PMC6266123.

Christi Buck
Christi Buck, RDN, LD, CLT
Registered Dietitian Nutritionist
Certified LEAP Therapist


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