Vitamin D is vital to health; there are vitamin D receptors in almost every part of the body. It is involved in nervous system, cell growth, reducing inflammation and maintaining the calcium and phosphorus balance in the body.
Yes, vitamin D is known as the sunshine vitamin because our skin can produce it during the right conditions when we are in the sun.
Living in the northern hemisphere, sunscreen, wearing clothing that block the UVB rays can make it challenging to generate enough vitamin D from the sun.
In fact the actual amount of sun time a person needs in order to generate vitamin d varies depending on age and skin tone-the darker your skin tone the more sun time you need. On average most people would get adequate vitamin D during the summer if they were outside between 10-30min 2-4 times per week. (1)
You might be thinking, well if there is no sun then I will just eat my way to adequate vitamin D.
I would love to do that too, but that could prove to be challenging. Look at this list of some common foods and the amount you would need to eat in order to meet the Recommended Daily Intake of 600IU (international units) is: 14 eggs, 15-7 ounce servings of pork, 10-5 ounce cans of tuna fish, 86-1 cup servings of (un-sunned) whole button mushrooms.
Eating salmon or sunned mushrooms everyday is your only option.
According to the USDA database: 1-4ounce serving of salmon or 1.5 cups of (sunned) whole button mushrooms would provide the recommended 600 IU’s.
Should I supplement and if so, what kind D2 or D3?
Ultimately, if you do not eat very specific foods, live in the southern hemisphere and go outside 2-4 times per week, then add a dietary supplement to our diet. The most bioactive form is D3, and that comes a variety of animal sources. The D2 form comes from UVB exposed mushrooms and is vegan. (2)
Is there such a thing, as too much vitamin D? Yes, play it safe and take less than the tolerable upper limit unless a doctor recommends more. (3)
Tolerable upper intake level has been set at 4,000IU for children over 9y and adults. Toxicity has been documented with intake of 10,000IU+ per day in as little as 3 months. Symptoms are not always obvious and take time to manifest. Worst case scenario is kidney problems, hyper calcemia and calcification of soft tissue.
- Publications, H. H. (n.d.). Time for more vitamin D. Retrieved June 22, 2017, from https://www.health.harvard.edu/staying-healthy/time-for-more-vitamin-d
- For health professionals: Council position statement on supplementation, blood levels and sun exposure. (n.d.). Retrieved June 22, 2017, from https://www.vitamindcouncil.org/for-health-professionals-position-statement-on-supplementation-blood-levels-and-sun-exposure/
- How do I get the vitamin D my body needs? (n.d.). Retrieved June 22, 2017, from https://www.vitamindcouncil.org/about-vitamin-d/how-do-i-get-the-vitamin-d-my-body-needs/