The Skinny on Vitamin D

What’s the deal on Vitamin D?   Should I check my levels?  Can I just get it from being in the sun daily?  How much is enough?  Where else can I get Vitamin D?

These are some common questions I get daily about vitamin D.  So here’s the skinny on Vitamin D.

What is Vitamin D? Why do we need it?

Vitamin D is a a potent neuroregulatory steroidal hormone that influences nearly 3,000 of your 25,000genes.1 It  turns on and off genes that can exacerbate — or prevent — many diseases.  Our body will not work correctly if we do no get enough.  We now know that mild deficiency can cause a range of chronic disease including osteoporosis, heart disease, blood pressure issues, impaired immune functions, autoimmune diseases like diabetes and multiple sclerosis, and even cancers like breast, colon, lung, lymphoma and prostate.

Where do I get Vitamin D?

The major source is your skin.  When the surface of our skin is exposed to UVB light, it converts a chemical compound to Vitamin D3, cholecalciferol.  If we are indoors all the time, or only outdoors in the morning or evening, we don’t produce enough Vitamin D.  You can also get vitamin D from food(limited), and supplements.

How much sun exposure is enough?

It’s different based on where you are in relationship to the equator, and how dark is your skin.  A light skinned person will full body exposure will make 15,000IU Vitamin D in 15-20 minutes in July at noon.  Darker skinned person can take twice as long to get same effect.

Should I worry about Skin Cancer?

Sun screen blocks UVB light and prevents Vit D being made.  However, it should be safe with 15 minutes of sun exposure before you apply sunblock.

Why is Vitamin D particularly important in pregnancy and newborn?

Having enough vitamin D during pregnancy reduces the risk of premature birth, low birth weight babies, Cesarean sections, and various others of the many complications of pregnancy. It also helps the unborn infant program its own body so as to reduce the risk of a host of disorders that may not appear until many years after birth. 4000 IU/day was demonstrated to be safe in a randomized trial to help pregnant women achieve a serum level of approximately 40 ng/mL. (Reference: Hollis, Wagner, Am J Obstet Gynecol. 2012 Nov 3) The American Academy of Pediatrics strongly recommends that all babies, whether breastfed or bottle fed, need supplemental vitamin D of 400 to 800 IU/d during the first year of life.

Which form of Vitamin D should I take?

Vitamin D3(cholecalciferol) is the form that our bodies make naturally on exposure to the sun. Vitamin D2(ergocalciferol) is synthesized from plant product precursors. Vitamin D3 is recommended because it’s more potent than vitamin D2.

How much Vitamin D do I need?

A person need 4000 IU/day from all sources to maintain a normal Vitamin D level in the blood.  If you are not exposed to sunlight regularly during the day, take 2000-4000IU daily.

According to the Institute of Medicine, there’s no observable adverse event at 10,000IU/day.

How much should I take?

Average requirement is about 35 IU/pound of body weight (75 IU/kg) per day, from all sources. So if you weigh 150lb, that’s 5000 IU daily Vitamin D3.  The best approach is still checking your vitamin D levels .

What level should my vitamin D be?

Aim for 40ng/ml or above of 25 OH-Vitamin D. Studies have shown that levels over 40 ng/ml 25 OH-Vitamin D are associated with lower risk of cancer such as Breast Cancer, decrease pregnancy comorbidities, type 2 diabetes.2

In summary, Vitamin D is a useful chemical our body needs, and it’s worth it to ask your doctor to check your levels in your next appointment, or supplement if you are not often exposed to regular midday sunlight.

 

 

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