12 June 2010
Catch the Sun
Peter Riddering, BHSc (CompMed), naturopath
Keywords: SAD, Seasonal Affective Disorder, Vitamin D, Saturated fats, low fat diets, sunlight, melatonin, Vita-lite, fish oil, vitamin D foods
The sun is now just about the furthest away from our New Zealand shores, it is also dipping closer to the horizon in the winter months. Especially now it is easy to get depressed a little as we are getting up in the dark and come home at nightfall. It is called SAD, short for Seasonal Affective Disorder or winter depression. The main contributors to SAD are reduced daylight hours and low fat diets. SAD affects you with depression, carbohydrate craving (a typical effect of low fat diet), increased need for sleep and lack of energy. It is a self-perpetuating cycle. Even here in NZ it is evident, more so in the South than here up North. The shortest day may be the darkest but it is not the coldest as the weather is 6 weeks behind the sun here in Auckland. Have you noticed that the moon is much higher in the sky in winter than in summer? They swap position.
The Vitamin D, Melatonin and Diet connection
With the reduced sunlight (read reduced vitamin D production) and colder temperatures comes the reduced immune response to flues and head colds. SAD is emphasised by the following factors: increased melatonin, low cholesterol, low fat diets and sun block, and weight gain. These are all related. Not many health professionals have drawn the connection with low fat diets. You can raise your vitamin D level in several ways:
- 1 - Direct Sunlight exposure, this alone provides in summer all the vitamin D the body requires.
- 2 - Increase blue spectrum light. Blue light reduces melatonin: a sleep hormone produced in the pineal gland in the brain by reduction of blue light (setting sun and night). Did you know that setting your computer up with more blue light increases productivity? Use full spectrum light bulbs for the same reason and spurs your work mates to greater productivity. Google f.lux for this.
- 3 - Eat right and include some saturated fats and food high in vitamin D.
- 4 - Replace your light bulbs with good broad spectrum lights.
- 5 - Supplement with vitamin D and/or
- 6 - Supplement with 1000 to 3000mg fish oil per day.
Alternative light sources
Not all light is the same. Light is rated in degrees Kelvin (k). The white sunlight will fragment into a spectrum of all colours like a rainbow. A normal household incandescent light bulb (approx. 4100K) has a colour spectrum towards the red and green with less blues does not create a true rainbow spectrum. Neither do those long fluorescent tubes with a harsher unflattering colour temperature lacking in reds and greens. The new broad-spectrum lights, like the Viva-lite, are simulating the colour of sunlight including the same near UV and mid UV range. When you put this light through a prism its spectrum is near identical to a rainbow. It is the unique matching with sunlight that makes it stand apart from ordinary light. Both broad spectrum lighting and sunlight (at 5500K) are scientifically reported to help with lowering Stress hormone, Mood improvement, Fewer headaches, Slower aging of the retina, Increased productivity, and Reduced eye strain, increased Vitamin D production in the skin.
A short synopsis of vitamin D:
Vitamin D is essential for many body systems. It is a prohormone with several active metabolites achieving calcium absorption from intestine, promote normal bone formation through the parathyroid, and stimulating immunogenic as well as anti-cancer/tumour activity. Vitamin D is a fat-soluble vitamin that is naturally present in some foods. Ultravioloet rays from the sun on the skin convert cholesterol to 7-dehydroxycholesterol, this is then converted in the liver to an active form (25-hydroxy vitamin D3), and also in the kidney to form 1,25-dihydroxy vitamin D, also known as calcitriol, the regulator for bone remodelling. A low cholesterol diet (translate low saturated fat diet) therefore reduces the chance of vitamin D production.
Supplementation with vitamin D as suggested by Dr Mercola (Google this great website) for an adult is up to 5000 IU per day. Medical and nutritional textbooks advise adult doses of 5 to 15 microgram (between 200 and 600 IU), in my opinion this is not enough. Direct sun exposure, 20 minutes per day on arms and face, can eliminate the dietary requirement of vitamin D. Note that if you avoid dietary fats AND sun exposure there obviously will be a greater chance for deficiencies! Diseases Vitamin D deficiencies are closely implicated in a large number of diseases: Immune system deficiencies, cardiovascular diseases, cancer, osteoporosis, diabetes, arthritis, osteoporosis and mental disorders. All these are on the increase. Now guess why? Over the last 50 years changes in everybody's life style have been dictated by medical authorities: diet, sun exposure, and fear mongering of genetic disorders (yes, this is already happening).
Foods and supplements
Best foods to eat are cold-water ocean fish such as salmon, sardines, herring, and mackerel, foods with saturated fats, butter, eggs; milk and orange juice are now being fortified but both of these are suspect food sources because they are immunologically destructive. There is nothing wrong with eating saturated fats as long as you stick to a calorie ratio of 40% carbohydrate, 30% protein and 30% fat or zone type diets.
If you are a vegetarian and avoid the sun as well as milk and animal fats your vitamin D intake is at risk, especially in winter. When you eat 1.5 kg of beef, 2 kg of corn oil, or 100 kg of cabbage you get the RDA for vitamin D. I wonder who would eat that much of these foods. However the same RDA is reached with 50 gram of salmon, or 2 grams of cod liver oil. Think twice when you have a strict vegetarian diet!
Body Stores.
Vitamin D is stored in our blood for a few weeks and in body fat for a few months. The Vitamin D levels decrease in winter and spring and typically there are seasonal increases in depression, paranoia and schizophrenia, cancer, and immune deficiencies (flues and colds).
If you suffer from these or a combination of these conditions it will be worthwhile to find out what your Vitamin D level is. You might need 4-5 times the amount recommended. The normal level of 25-OH D should be near 60ng/ml. Vitamin D toxicity is one of the most dangerous vitamins as it upsets the total calcium balance. Excess vitamin D intake can result in permanent deposits of minerals in lungs, heart, and kidneys; toxicity includes symptoms of nausea, vomiting, pain in joints and loss of appetite.
To recap:
By now the light should be on: catch your sunlight, avoid sun block, supplement and replace your indoor lights with Full spectrum Viva-lite light bulbs. The most important winter supplement is Vitamin D (or take 2 to 3 omega-3 fish oil capsules/day), eat real foods that have vitamin D (oily fish, butter and saturated fats to zonal quantities).
If you are suspecting you are suffering from a combination of depression, sleep problems, repeated colds and flues I strongly advise you to see a professional for help.
There is a shortened version of this article on the blog page.
References: * Whitney EN, Rolfes SR, Understanding Nutrition, 9th edition 2002, Wadsworth/Thomson, Belmont, CA, USA.
* The Merck Manual 17th edition, 1999, Merck Research Laboratories, whitehouse station, N.J., USA
* Brody Tom, Nutritional Biochemistry, 2nd edition, 1999, Academic Press, San Diego, USA
* Porth, Pathophysiology: concepts of altered states, 6th edition, 2002, Lippincott Williams & Wilkins, Philidelphia, USA
* Galbraith, Bullock, Manias. Fundamentals of Pharmacology, 4th edition 2004, Pearson education, Australia.
* And Various web sites available on request.