Shine a little Vitamin D on me!

Quick Facts about Vitamin D:

  • Vitamin D is in fact not an essential vitamin because our bodies can synthesize it from the sunlight.
  • There are two forms: D2 and D3.  D3, cholecalciferol, is the more bioactive form of vitamin D and comes from animal products (primarily) and UVB exposure.  

I know you are at the edge of your seat wondering “How does our body absorb something from UBV light and make it available for metabolic utilization?!”  Ok, maybe not in those exact words, but the answer put simply:  When the UVB rays hit your skin it is converted into a cholesterol derivative, which is then converted into D3.  The active form of D3 is actually a hormone called calcitriol. 

Main Functions of Vit D:

  • It helps to regulate calcium and phosphorus blood levels.  Vitamin D helps the body to absorb calcium and phosphorus, which is very important for bone growth and muscle contraction.
    • Fun fact! Do you get little twitches or fasciculations in your muscles that are involuntary, especially after a work out?  This is usually an electrolyte imbalance, and the most common deficit substance is calcium.  If you think you are well stocked in calcium, but not vitamin D, then your body will not adequately absorb calcium, thus muscle spasms occur.
  • Vit D helps to modulate cell growth, neuromuscular and immune functions, and reduces inflammation (1).

Cell growth and degeneration are regulated by gene encoding proteins which have receptors for the active form of vitamin D.  Properly functioning receptors supplied with adequate vitamin D will keep bone, collagen and other tissue types healthy and strong (3).

Sources of Vit D:

  • One of the top sources is from fish/shellfish oils (cod, mackerel, salmon, and tuna), but can also be found in butter and egg yolks.
    • Cod liver oil is an excellent source because you get one of the best sources of omegas and vitamin A along with the vitamin D.
  • It can also be found in fortified foods such as dairy, and orange juice (beware of sugar content with this one!).
  • SAFE sun exposure can actually (brace yourselves) reduce your risk of cancer and suppress tumor formation in skin cells.  Remember we discussed earlier that vitamin D helps to regulate healthy cellular growth and degradation?  Check out this article to read more about this fact.
    • Remember! Don’t go out and get all the sun you possibly can in one day.  Build a nice base tan, and ease your skin into sun exposure.  When you burn you are damaging your skin cells, and this can raise your risk of skin conditions including cancer.
    • Sunscreen and sunblocks can decrease vitamin D absorption, however they protect you from overexposure of UBA and UBV rays.  Sunscreen can be toxic for the skin because of the chemicals it is made out of, which our skin absorbs.  If you want protection buy sunBLOCK which allows for minimal skin absorption of the lotion and harmful UV rays because it mostly reflects the sun rays.  Natural sunblocks can be found at natural food stores or a dermatologist. 

Daily intake of vitamin D by Food and Nutrition Board:

400-800IU (under 50)     800-1,000IU (over 50)

Vitamin D Council Recommended Daily Intake:

5,000-10,000IU/day for adults (1,000IU/25 pounds for children)

***Note: vitamin D is fat soluble so your body can have a difficult time getting rid of it.  It is highly recommended that you take no more than the upper limits of the suggested dosage unless your health care professional says otherwise.  That being said, it is best to take vitamin D with meals that contain fat.  Supplementation intake is especially good during times of the year when sun exposure is less.


Best times of sun exposure?

Mid-day is optimal because the sun’s rays are efficiently entering the earth’s atmosphere (2).  Rule of thumb:  If your shadow is longer than you are tall, your absorption will be less (2).


Skin types and absorption:

The more pale your skin, the more easily your absorb UV rays, thus less time is needed in the sun (2).  When your skin turns slightly pink or deepens in color slightly you know you are at your daily intake that is necessary.  For some people, this could be 15 minutes, while others closer to an hour.


  1. NIH - Vitamin D Facts Sheet for Health Professionals
  2. Vitamin D Council.  How do I get the vitamin D my body needs?
  3. 3. Carlberg, C. Genome-wide (over)view on the actions of vitamin D. April 29, 2014.

By: Vanessa Nordin, DC at Positive Motion, CSV Health/Lifestyle Coach