Have you heard about the benefits of Vitamin D? Are you curious about what it is and how it works? How do you know if you are Vitamin D deficient? Is being outside important for Vitamin D levels?

Summer is here and it’s the time for fun in the sun and heading outdoors to soak up its warm rays!!!!!

One is capable of producing greater than 10,000 IU of vitamin D daily, but what actually influences production? There are many factors with the most well known being the angle of the sun’s rays, which is affected by the time of day, season and latitude. In turn, these factors determine the amount of UVB exposure to reach the skin and stimulate Vitamin D production in the body.

What are UVB rays? They are the portion of light that stimulate vitamin D production and are diffused primarily at the early and latter parts of the day, during winter months and at latitudes north of the equator.

Need to consider skin type? Those with darker skin pigmentation require longer sun exposure time for vitamin D synthesis. Therefore, the combination of skin type, latitude and season must all be factored into determining the necessary length of sun exposure time for an individual to produce optimal amounts of vitamin D.

What about sunscreen, tanning beds and Vitamin D? Many of us use sunscreens that even at a factor of 8, block 95% of UVB rays. Other culprits include: clouds, air pollution and glass windows. (we need direct skin exposure). UVB tanning beds are not the best option as the rays should be directly from the sun, they are costly, associated with accelerated aging of the skin and increased risk of skin cancers. Therefore, about 20-30 minutes of sun without sunscreen should be enough to generate adequate Vitamin D, then cover up with sunscreen, a hat, etc.

Where does vitamin D come from?

Vitamin D is a fat soluble vitamin and pro-hormone that exists as Ergocalciferol (Vitamin D2) and comes from plant sources whereas cholecalciferol (Vitamin D3) is found in wild salmon, cod liver oil, sundried shitake mushrooms, sardines, mackerel, tuna and fortified food products. There are many vitamin D supplements on the market. Be aware that they are not all made equally, so one needs to be cautious with the brand. Also, remember to take your vitamin D supplements with food!!!!

What roles does vitamin D play?

Bioactive vitamin D binds to specific receptors in almost all the tissues in our bodies thereby regulating the function of a variety of tissues. The primary function of vitamin D is to maintain healthy calcium and phosphorus in the blood to support bone mineralization, proper nerve and muscle function as well as cell functions. It acts as a hormone, enhancing the absorption of calcium and phosphorus in the small intestine. Therefore, without Vitamin D, only 10-15% dietary Calcium is absorbed.

However, vitamin D’s role has more diverse health-related issues such as inflammation (probable at the cause of many diseases), insulin resistance, heart activity and blood pressure, peripheral neuropathies, autism, brain health (higher score on mental function testing), polycystic ovarian syndrome (PCOS), PMS, Menopause, depression, skin rejuvenation, dementia-related conditions, bone fracture repair, etc.

In recent years, scientists have discovered some of the profound effects that Vitamin D has on the immune system with evidence it may help with autoimmune conditions. Vitamin D supplementation has been associated with beneficial effects in a number of conditions including, influenza to cancer/chemotherapy. Some of the immune conditions associated with vitamin D intake include: multiple sclerosis, lupus, (SLE), fibromyalgia, rheumatoid arthritis, dermatological issues (i.e. psoriasis), diabetes type 1 and type 2, infectious diseases, amongst others.

Preliminary evidence suggests vitamin D may aid in cancer prevention by blocking cell differentiation and growth. Specifically, from a study published in the American Journal of Clinical Nutrition, it was found that vitamin D may reduce the incidence of many types of cancer.

In a double-blind, randomized, placebo-controlled trial of 104 women given vitamin D, it was reported they were 3 times less likely to report cold and flu symptoms. “A low dose (800 IU/day) not only reduced incidence, but also abolished the seasonality of reported colds and flu. A higher dose (2,000 IU/day), given during the last year of their trial, virtually eradicated all reports of cold or flu”.

“Our paper discusses the possibility that physiological doses of vitamin D (5,000 units a day) may prevent colds and flu, and that physicians might find pharmacological doses of vitamin D useful in treating some of the people who die in the world every year from influenza. The possibility was also raised that influenza is a symptom of vitamin D deficiency”. (Epidemic Influenza and Vitamin D. Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, and Giovanucci E. Epidemiol Infect. 2006 Oct. 2007; 135 (7): 1095-1098.)

Vitamin D is also making the news in several roles involved with optimal women’s health conditions, including pregnant women. It has been seen that if the pregnant mom is deficient in Vitamin D, so will her baby.

Since it regulates over 200 genes that control important pathways in the body, as we age, we lose some of our ability to synthesize and absorb vitamin D. This supplement works as a key factor in maintaining hormonal balance and a multiple of studies have shown a correlation between higher levels of vitamin D and leaner body mass which may aid the success of an overweight individual participating in a weight-loss program.

How much of Vitamin D is enough?

Although the RDA requires about 400 IU/day, many studies have found this amount is barely enough!! After obtaining a blood test, follow the chart below.

Reference Ranges:

Supplement: Retest

Severe Deficiency <20ng/ml 5-10,000 IU 3 months

Insufficiency <20-70ng/ml 5,000 IU 3-6 months

Optimal 70-100ng/ml 2,000 IU 6 months


Check out this informational 11 minute presentation on Vitamin D at:


Another resource for you is this article by Dr Joseph Mercola:

"The Stunning Effect of this Single Vitamin on Cancer..."

Author's Bio: 

Iris Rosenfeld, DC is a bestselling contributing author and was awarded the Woman of the Year. Since beginning her practice in 1985, her services are tailored to meet one’s needs structurally, nutritionally and emotionally through eliminating the interferences that lead to dysfunction, pain and disease. She utilizes different techniques to empower one to achieve greater well-being. To learn more about upcoming seminars, receive free newsletters and create miraculous breakthroughs in abundant longevity health and vitality, go to www.driris.com.