Dukan Diet

Does Dietary Inflammation Reduce Skin Production of Vitamin D?

The media discovered the vitamin D deficiency pandemic last week. Amazingly researchers were recorded on camera saying that the D deficiencies are caused by insufficient exposure to ultraviolet in sunlight and inadequate consumption of vitamin D-laced milk. Have all of these people been avoiding the biomedical journals?

Have they noticed that my tan improved since I started eating anti-inflammatory?

Let’s shine some sunlight on these knowledge deficiencies:

• Serum vitamin D levels have been dropping (as chronic inflammation has been increasing) over the last three decades -- has something changed in our diets?
• Vitamin D deficiencies occur globally (not restricted to Northern latitudes or winter) -- related to diet?
• Women are more vulnerable, because of cultural modesty in some countries, but males are still D-deficient.
• A subset of people exposed to ample sunshine are still D-deficient.
• Vitamin D deficient individuals also have elevated TNF.
• Vitamin D deficiency and inflammation are risk factors in the same diseases.

It seems that the simplest conclusion is that chronic inflammation leads to vitamin D deficiency, even though vitamin D deficiency may also contribute to inflammation.

This also probably means that chronic inflammation makes it harder for skin to produce vitamin D during exposure to sunlight.

One would expect those who are inflamed to get sunburned more readily and people who eat plenty of omega-3 rich seafood probably produce more vitamin D, even if they are not in the sun as much.

Inflammatory starvation (or American fast food) diets high in starch and omega-6 vegetable oils, should produce vitamin D deficiency even on the Equator.

We should not be surprised that inflammatory degenerative diseases are associated with vitamin D deficiency. It would be interesting if vitamin D supplementation to eliminate deficiency, reduced inflammation and reversed degenerative disease.

Do statins reverse vitamin D deficiencies (and improve tanning) as they lower inflammation? [Statin lowering of LDL is unrelated to reduction in cardiovascular disease. Only the anti-inflammatory side-effect is important.]

Does NFkB activation (inflammatory signaling) inhibit vitamin D receptor activity and vice versa?

You can forget all of this confusion, if you just stick with an anti-inflammatory diet (that includes vitamin D supplements) and exercise frequently in the great outdoors.

Vitamin D has been talked about quite a lot in the past several years. Most commonly it comes up when talking about bone health. However, Vitamin D does have many other functions besides bone health, including sports performance. So, let’s break it down:

• Vitamin D is a fat soluble vitamin that is also a hormone.
• There are two main forms of Vitamin D: D2 (ergocalciferol) which is the inactive form and D3 (cholecalciferol) which is the active form.

• People get Vitamin D mainly from exposure to the sun or ultraviolet B (UVB).
• The recommendation for sun exposure is 5 -30 minutes per day between the hours of 10am -3pm. Age, skin tone, location and what season it is may change sun exposure required. Therefore, people that train inside, partake in winter sports and live in northern latitudes might be more lacking in exposure.
• Vitamin D is also found in certain foods including: fatty fish (salmon, sardines, mackerel, etc.), dairy products and fortified foods and beverages. However, it’s fairly difficult to reach the recommended daily allowance (RDA) with food alone (the RDA is 400-800 IU/day).

• Vitamin D has been shown to play a role in prevention of: cancer, heart disease, autoimmune disease, infection, diabetes and bone disease (including fractures and stress fractures).
• In addition, Vitamin D plays a role in muscle strength, muscle mass, muscle function, balance control, endurance, speed, reaction time and inflammation.
 • Interestingly enough, more than 77% of Americans are Vitamin D deficient which probably includes athletes.
 • Deficiency may cause muscle injuries, stress fractures and respiratory infections. Therefore, it is very important to check what our Vitamin D levels are.

 • Vitamin D is tested by taking a blood sample of 25(OH)D.
 • Deficiency is defined as < 20 ng/dL of 25(OH)D, insufficient is 20.1-29.9 ng/dL and sufficient is > 30 ng/dL. However, it seems that the optimal level for athletes is higher at 40- 50 ng/dL. There is no apparent benefit of having levels higher than 50 ng/dL.
 • Supplementation of Vitamin D is recommended in case of deficiency. To know exactly how much, consult with your physician and registered dietitian.

 So, since summer is just around the corner, make sure you play outside and get at least 10-15 minutes of sun exposure during the peak hours with no sun screen to get some good quality Vitamin D. And don’t forget to apply sun screen, if you are going to be outside for a long time. In addition, make sure you eat high sources of Vitamin D including fish, dairy products and fortified foods and beverages. You can get your Vitamin D level tested and consult with a professional for further guidance.

Written by: Noaa Bujanover - MS, RD, CSP, LD/N, CSCS