Vitamin D - The Essentials

Sometimes health care providers may assume that with all the technology constantly at our fingertips, we know what certain nutrients are or we can do a quick search to learn about it.

That isn’t actually the case. Since there can be conflicting information on your first three google searches it can be overwhelming and sometimes confusing to decipher what is the essential information that you should know. This post is only the essentials you should know about Vitamin D.

Name - Vitamin D, also known as calcitriol. A fat soluble vitamin. This means if you don’t consume fat in your diet, your body will have a hard time absorbing fat soluble vitamins, including vitamin D.

Why we need vitamin D - Maintains blood calcium levels by increasing absorption of calcium. Recent research shows vitamin D may play a role against cancer, heart disease, fractures and falls, autoimmune disease, inflammation and depression (1). Vitamin D enhances calcium bioavailability by 30-40% and phosphorus more bio-available by 30-40% depending on the person.

What happens when you don't get any or not enough - Soft bones, osteomalacia, symptoms of depression

Food sources - Think of animal sources!

1. Egg yolks

2. Fatty fish (salmon, sardines, cod liver oil)

3. Fortified milk

4. Mushrooms from the same UV conversion that occurs in our skin!

The science of Vitamin D conversion in our body - UV rays convert cholesterol underskin from 7 dehydrocholesterol to cholecalciferol ( vitamin D3). To make functionally active, liver turns Vitamin D3 into 25OHD (Calcidiol) and kidney turns 250HD to 1,25OH2D ( calcitriol) the functionally active form of vitamin D. Either way you decide to get vitamin D, it is biologically inert and has to be activated through processes inside the liver and kidney before it can be used by the body. Ergocalciferol (Vitamin D2) is the name for the synthetic version of vitamin D. Treatment for deficiency includes vitamin D2 and D3 supplementation. Vitamin D produced in the skin lasts twice as long as vitamin D ingested (1).

Do we need more vitamin D than what we get from the sun? - Depends, the most common way people get enough vitamin D is by sunlight exposure. If you have less sunlight exposure, you may want to think about increasing vitamin D in your diet. People who may benefit from vitamin D supplementation and should speak to their health care provider about the best vitamin D supplement for them include, gastric surgery patients, people with fat malabsorption, people who limit sun exposure including sunscreen use, or breastfeeding.

How much should we be getting - The current recommended dietary allowance (RDA) for 19-69 year old is 600 IU (15 mcg) daily for both men and women. For reference 1 egg yolk contains approx 37 IU of vitamin D. RDA is recommended daily intake of nutrients for healthy people and is developed by the Food and Nutrition Board of the National Academies of Sciences, Engineering and Medicine. Therefore this is not recommended for anyone who has been diagnosed with a specific illness. Do not take more than 1000 IU without medical supervision (1).

Recommendation - If you are interested in taking a new supplement it is best to speak to your health care provider. Most cases, supplements can be tailored to your individual needs because not everyone will have the same effect from the same recommended intake. Your health should be tailored to your unique needs.

If you are interested in taking a new supplement it is best to speak to your health care provider.

Eliminating the fluff and going directly to the essential information using evidence based sources. If you liked this post and have other nutrients that may have conflicting information and you want to know the essentials of it, let me know! Keep an eye out for these posts. I will include in the title - the essentials

1. Nair R, Maseeh A. Vitamin D: The "sunshine" vitamin. J Pharmacol Pharmacother. 2012 Apr;3(2):118-26. doi: 10.4103/0976-500X.95506. PMID: 22629085; PMCID: PMC3356951.

2. Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Ross AC, Taylor CL, Yaktine AL, et al., editors. Dietary Reference Intakes for Calcium and Vitamin D. Washington (DC): National Academies Press (US); 2011. Available from: https://www.ncbi.nlm.nih.gov/books/NBK56070/ doi: 10.17226/13050

3. National Research Council (US) Committee on Diet and Health. Diet and Health: Implications for Reducing Chronic Disease Risk. Washington (DC): National Academies Press (US); 1989. 11, Fat-Soluble Vitamins. Available from: https://www.ncbi.nlm.nih.gov/books/NBK218749/