What’s the Buzz About Vitamin D?

Photo by Bonguri.

Vitamin D has been all over the news as the latest nutrient whose Recommended Daily Allowance has come under great scrutiny.

Dietary vitamin D is unique in that it is not actually a vitamin and would be better classified as ‘pro-hormone D’.   We can thank Sir Edward Mellanby for the mishap in nomenclature going back to 1919 when the first notion of vitamin D being activated by sunlight was established.  In our closest attempt to imitate plant photosynthesis, when sunlight strikes our skin a series of chemical reactions takes place and vitamin D is converted to a hormone called cholecalciferol (D3).

Semantics aside, vitamin D is fat soluble so your best food sources are from animal fats; fatty fish (salmon, mackerel), egg yolks, butter, liver, and full fat milk.  Now the reason I bring this up is that the quality and quantity of saturated fats has greatly decreased since the low-fat-spandex-aerobics craze of the 80′s (apologies for the mental imagery).  Sure, foods are often fortified with vitamin D, but this process of refining and then fortifying creates anything but a whole food product.

Historically the primary evidence of vitamin D deficiency has been rickets and stunted bone development in children.  Generally speaking this was treated with either direct sun exposure, or light boxes designed to provide adequate levels of UV light sparking the chemical conversion to D3.

I seriously doubt that historical D deficiencies were due to a dietary lack of vitamin D, as our ancestors consumed very adequate portions of saturated fats (which we are now learning are not the evil doing artery clogging grease they were once thought to be).  With the RDA slowly rising it really makes me wonder whether part of the reason is that we have severely cut off our supply of raw materials, namely high quality, organic saturated fats.

You need 15 minutes of sun exposure per day to activate the dietary vitamin D.

Eating whole animal foods provides a large amount of precursors that are converted to D3 with the sun exposure.  Of course, it is essential to balance the necessary 15-20 minutes of sunscreen free sunshine a day (more if you have darker skin) and the increased risk of skin cancer (if you’re going to spend hours in the sun get a fur coat like all the other mammals).

Do you know how the RDA was established? The Food and Nutrition Board of the Institute of Medicine (IOM) set the AI (adequate intake) levels assuming NO vitamin D was being synthesized in the skin through exposure to sunlight.  This was back in 1997 and since then we have seen the RDA climb from 200 IU’s upwards.  The new official guidelines from the IOM won’t be released until May 2010 but until then they are recommending 400 IU’s for kids under 10.  The chairman himself, Dr. Frank Greer, takes 1000 IU”s of vitamin D a day which is an ideal dose for adults.

What it does for you:

• Increase energy
• Lift mood
• Regulate calcium & phosphorous
• Increase immunity
• Increased bone health
• Prevents cancer

It really isn’t very difficult to get vitamin D into your diet if you are allowing yourself consumption of whole animal fats, here are some examples:

• 1 Egg yolk 25 IU’s
• 3 oz can of sardines 230 IU’s
• Liver
• Cod liver oil (make sure the product has not had the natural vitamin D stripped out and a synthetic version put back in)
• Yes, of course all those fortified foods

It is then very easy to activate the vitamin D with 15 minutes of sun a day

• frisbee
• nothing – 15 minute sun bath
• walk, jog, stroll
• cup of tea outside
• tai-qi, qi-gong

In an effort to simplify RDAs, statistics, news, mixed information, and the numbers:  Whole foods and some sunshine – Doctors orders.

Dr. Nishant Rao is a co-founder of WellWire.com. He is a well-traveled naturopathic doctor and new father, practicing an integrative approach to create wellness in and around Los Angeles. Become a patient or discover his practice.