When we think of Vitamin D, we often think in terms of preventing osteoporosis and maintaining the health of your bones. However, the effects of vitamin D on our body goes way beyond those on bones and current research is finding so many other incredible effects this vitamin has on the human body. As a matter of fact, it is so important it is considered to be not only a vitamin, but a hormone! Interestingly, vitamin D is similar to many of our steroidal hormones, as it is also derived from cholesterol just like, cortisol, estradiol , testosterone and many others. ( Please refer to our prior newsletter for July/August on hormones).
Vitamin D is unique in that our bodies can generate this vitamin if our skin is exposed to proper levels of sunlight and is known as the “sunshine vitamin”. However, most of us even here in Arizona do not allow proper exposure of our skin to the UVB rays from sunlight. We often spend most of our time inside, are covered by clothing and lather large amounts of sunscreen to block the skin’s ability to manufacture vitamin D. We will discuss safe sunlight exposure later as too much does increase the risk of some skin cancers.
Very few foods natural contain vitamin D. However, it can be also derived from our diet. It is found naturally in larger amounts in fatty fish such as salmon, tuna, sardines, and mackerel. Smaller amounts are found in cheese, butter, cream, egg yolk, beef liver, portabella mushrooms and oysters. Most Americans probably obtain vitamin D in their diet from fortified milk and cereal products. However, these amounts may not be sufficient to raise your levels to healthful levels. Besides, many of theses fortified foods are highly processed and some still use vitamin D2 (ergocalciferol) rather than the more useful form known as vitamin D3 or cholecalciferol. D3 is much more effective and smaller amounts are needed to improve our health compared to the synthesized vitamin D2. Be aware that many physicians still recommend vitamin D2 rather than vitamin D3 in supplement form. This may be a hold over from older studies involving the disease rickets. Newer studies clearly show that the D3 form is superior.
What truly makes vitamin D incredible is its hormonal characteristics. It is one of the few besides vitamin A that can enter your cells and have a direct affect on the functioning of your genes. It is estimated that there are about 30,000 genes in our cells and vitamin D can have a direct affect on about 3,000 of those genes! Even more incredible is that virtually all cells in the human body have receptors for vitamin D, meaning that almost all our cells are responsive to vitamin D! It has been shown through research that vitamin D not only affects bone tissue, but breast, colon, kidney, liver, pancreas, lung, prostate, skin , stomach, eye, brain and uterine tissue. Incredible!
RISK FACTORS & SIGNS OF DEFICIENCY OF VITAMIN D
INCREASE RISK FACTORS
- If you are overweight or pregnant
- If you work inside and spend most of your time indoors
- If you have darker skin pigmentation
- If you are older than 50 years of age
- If you routinely use over SPF 8 sunscreen and cover up when outdoors
- If you have had gastric bypass
- If you have an inflammatory bowel disease such as Crohn’s, IBS or Celiac disease
- Strict vegetarian diet
- Liver or kidney disease
- Living in northern latitudes
SIGNS OF DEFICIENCY
- You develop frequent colds
or flu
- You are chronically fatigued
- You suffer from chronic low back pain.
- Chronic muscle pain and stiffness
- Diagnosed with osteopenia, osteoporosis
Please note that in many cases of deficiency there are no apparent symptoms or they may be vague.
CONDITIONS ASSOCIATED WITH VIT. D DEFICIENCY
The reason this list is so long is that vitamin D has such a huge impact on many of our genes at a cellular level and that most organs and tissues respond to vitamin D levels. Remember this vitamin acts more like a hormone.
Here are some conditions that may respond to vitamin D:
Alzheimer’s, asthma, autism, back pain, burns, cancer, colds, congestive heart failure, dementia, dental cavities, depression, diabetes 1&2 , eczema, fatigue, high blood pressure, insomnia PCOS, hearing loss, influenza, macular degeneration, migraines, multiple sclerosis, muscle pain, osteomalacia, osteoporosis, periodontal disease, rheumatoid arthritis, rickets, seasonal affective disorder, seizures, and tuberculosis.
As research progresses there will probably be other conditions that will respond favorably to appropriate vitamin D therapy.
PROPER BLOOD LEVELS OF VITAMIN D
The only truly way of identifying vitamin D levels is a blood test monitoring an intermediate form of vitamin D3 and not cholecalciferol (we will explain this later). This intermediate form you will see on a blood test as 25(OH) D. It is interesting to note that the acceptable levels of 25(OH) D have been raised in the last few years. More recent research has found the past levels were much to low. There is some debate on proper levels, but most agree on deficient and insufficient levels. The following levels have been taken from a nationwide company called LabCorp:
- Deficient – 0-5 ng/ml
- Insufficient – 5-32 ng/ml
- Low level – 32-40 ng/ml
- Sufficient – 40-100 ng/ml
- Toxic – greater than 100 ng/ml
They use this form to measure as it is more “stable” in the blood stream. This does not measure vitamin stored in fat tissue nor the actual active form of vitamin D called 1,25 (OH)D or calcitriol. This is the actual form that enters the cell and affects our genes.
VITAMIN D – BEGINNING TO END
Firstly, the main sources of vitamin D comes from our skin when exposed to ultraviolet B rays or UVB from the sun and from sources in our diet that are absorbed through the intestines. This form is called Vitamin D3 or cholecalciferol. It is then transported in the blood to the liver. The liver now converts this to the form of vitamin D that we measure in the blood called 25 (OH)D or calcidiol. It is then transported to the kidneys for the final conversion into 1,25 (OH) D or calcitriol. This is the active form of vitamin D that enters your cell and leads to the beneficial effects of this hormone/vitamin.
As you can see it is important that proper kidney and liver function exists so that this process proceeds smoothly and uninterrupted. What can influence this process is also a hormone released by small glands around your thyroid called the parathyroid glands. This gland releases a hormone called PTH that increases the active form of vitamin D.
Active vitamin D then affects calcium balance throughout the body and most are aware of its effects on bone. It inhibits cells from turning into cancer cells. It modulates many of the various immune cells such as macrophages, T lymphocytes and many others. It is involved with the ability of the pancreas to produce insulin. It is also directly involved with regulating blood pressure. Incredible!
VITAMIN D – SUNLIGHT & SUPPLEMENTS
The most effective way of obtaining vitamin D is from exposing the skin to UVB rays from ordinary sunlight. There is no risk of your body overproducing vitamin D when exposed to sunlight as this process is self regulated. The skin will also manufacture cholesterol sulfate that is water soluble ( not stored in fatty tissue) and easily enters the blood stream and helps with cardiovascular and heart health.
There are several factors that influence UVB reaching the skin in the appropriate amounts. The highest amount of UVB rays occur between 11 am to 3pm. The reason for this is that if the suns rays enter the atmosphere at an angle, which happens early morning and later in the day, the UVB rays are unable to reach the surface of the earth. The further away from the equator you live the less the UVB rays reach the ground. The intensity of UVB rays are higher in the summer versus the winter. UVB rays are stronger at higher altitudes as well. Complete cloud cover reduces UVB rays by 50% and severe air pollution can reduce UVB by 60%. Furthermore, SPF 8 sunscreen reduces vitamin D production by 95%.
There is also a concern about too much sun exposure and the risk of increased skin cancer. However, in order to get adequate vitamin D you do not need to burn or darken your skin. In fair skinned people it may take only 15 minutes. If you are darker skinned it may take 1-2 hours of exposure. You will produce more vitamin D if you expose larger areas of the skin. You may have to expose the skin 2-3 times per week. You can certainly check to see if your “time in the sun” is adequate by running a vitamin D blood test after about 3-4 months. It is a good idea to protect some areas on the face especially around the eyes to avoid UVB exposure and wearing UV blocking sunglasses is also recommended to protect you against cataracts. With extended sun exposure cover up and find shaded areas. It is not recommended that you use most of the commercial available name brands as they contain many toxic ingredients. A good website to go to for recommended natural sunscreens is www.ewg.org.
The most effective oral form of vitamin D is D3 not the often prescribed form called D2. D3 should be fish oil based and emulsified. The Institutes of Medicine recommends, 600IU/day, over 70 years old 800 IU/day and a safe upper level of 4000 IU/ day. In many people these recommended amounts may not be nearly adequate to raise vitamin D levels and provide significant health benefits.