Vitamin D is an essential fat-soluble vitamin. It is formed naturally in the skin by exposure to sunlight, hence it’s nickname “The Sunshine Vitamin”. Someone with fair skin can produce up to 20 000 IU’s in just 20 minutes with full body exposure in peak seasons. However, for those of us living in Canada, the sun is not strong enough throughout mid-September to mid-May to stimulate adequate Vitamin D production and we experience a rapid drop in stores. Also, as we age, our bodies become less efficient at manufacturing vitamin D. Other factors for lower Vitamin D levels are having a darker skin tone and consuming a vegetarian or vegan diet. This puts us at risk for deficiency and a range of associated symptoms such as impaired immune system, brittle bones, low mood, etc.
Process
Vitamin D is produced when sunlight/ultraviolet rays converts cholesterol (D1/Cholesterol) in your skin into a form called “calciol”. The liver then converts it into another form called “calcidiol”. This form is inactive and is circulated and stored in the body. This is the form that is measured during blood tests. Then, it is up to the kidneys to convert “calcidiol” into “calcitriol”, its active form.
Types
When ultraviolet rays from the sun strike “ergosterol” in plant oils, D2 is formed. When they strike “7-dehydrocholesterol” on animal skin, D3 is formed. Vitamin D2 is generally formed synthetically from vegetable oils and is often used to fortify foods. Vitamin D3 is generally the preferred form.
Benefits
Bones, teeth, joints and muscles all require Vitamin D3 to remain strong and healthy as it is essential for calcium absorption and promotes mineralization. Those with Vitamin D deficiency have a higher risk of osteoporosis, fractures, rheumatoid arthritis, tooth decay, muscle cramps, bone pain as well as reduced muscle strength. It is said that when vitamin D stores are low, only 10–15% of intestinal calcium is absorbed, but when it is adequate, 30–80% of intestinal calcium is absorbed.
Vitamin D helps support normal functioning of the nervous system. It has been associated with the reversal of inflammation from Parkinson’s, Multiple Sclerosis and Age-Related Dementia. It can also help with Seasonal Affective Disorder (aka “winter blues”) in helping to improve mood as well as reducing the incidence of depression. It should be noted that depression and suicide peak between January and April. This is also when Vitamin D3 blood levels are generally the lowest.
Deficiency of Vitamin D has been linked to increased risk of heart attack. As Vitamin D regulates calcium absorption, adequate levels reduce the risk of calcification in the arteries and help control blood pressure.
Vitamin D is essential for the development of the brain, nerves, and skeleton. It also plays a role in helping to prevent bone loss and preeclampsia in pregnancy. Therefore, it is of utmost importance that pregnant/lactating women and children have adequate levels of Vitamin D.
Vitamin D is also helps promote healthy hormone function. It is essential for the production of thyroid hormones, and many people with low thyroid are vitamin-D deficient. In addition, it also helps normalize insulin secretion for people with type 2 diabetes!
Vitamin D has been shown to help support immunity as it helps white blood cells recognize foreign invaders and may also influence the release of protective proteins when needed. It can help prevent colds and flus, reduce severity of bacterial infections as well as decrease risk of autoimmune diseases!
In addition, Vitamin D3 has shown to improve lung function, especially in former smokers and inhibit excess skin cell growth associated with psoriasis.
Did You Know: Vitamin D is not only a vitamin, but a hormone? Every cell in the human body has receptors for Vitamin D3. It regulates cellular production of important nutrients and even affects gene expression (influences roughly 10% of your genes)!
Sources
Your body makes vitamin D, but only when your skin is exposed to sunlight. Some use UV emitting devices to get the same effect in the winter months. However, this nutrient can also be attained in small doses from certain foods such as fatty fish (like salmon), mushrooms, nuts, beans, egg yolks and liver. Supplementation is often recommended to ensure adequate intake when sunlight exposure and diet are deficient. Look for this in an olive oil base which is an excellent preservative and enhances the bioavailability of Vitamin D.
How much?
Current research has suggested that adults take up to 5000 IU’s daily in winter or whenever sun exposure is limited and in certain circumstances, even higher dosages may be recommended by professionals for therapeutic purposes. Ask a health practitioner for advice on what dosage you should be taking to meet your unique needs.