Article by Peter Hookes

More and more scientific evidence is accumulating showing the important role of vitamin D in the immune system. Plenty of studies are also supporting the role of vitamin D in prevention of common respiratory infections. One of the largest studies made has showed that people with the lowest blood vitamin D levels had significantly more recent colds or cases of the flu.Vitamin D is actually a group of fat-soluble prohormones. The two most relevant forms for humans are vitamins D2 (ergocalciferol) and D3 (cholecalciferol). Vitamin D2 is produced in some phytoplankton, invertebrates and fungi in response to UV irradiation. Vitamin D3 is produced in the skin of vertebrates due to exposure to ultraviolet B light from the sun. Vitamin D3 is also naturally found in fish and few other foods. The preferred supplemental form of vitamin D is vitamin D3 since it is the same substance as what is produced in human skin after sun exposure. Supplemental D3 is derived either from lanolin or cod liver oil extract.

Vitamin D level is determined by measuring serums concentration of 25-hydroxy-vitamin D, also known as calcidiol. It reflects to vitamin D produced in skin and that acquired through diet. A concentration above 15ng/ml (37,5 nmol/l) is usually considered adequate for those in good health. Levels above 30ng/ml (75nmol/l) are proposed desirable for achieving good health. Recent studies have shown however that level conventionally considered as normal is not the same as optimal level. According to latest research it seems reasonable to believe that values below are in fact more reflective to optimal vitamin D levels:

deficient <50ng/ml (<125nmol/l)optimal 50-70ng/ml (125-175nmol/l)treating cancer and heart disease 70-100ng/ml (175-250nmol/l)excess >100ng/ml (250nmol/l)

The late winter average vitamin D level in the United States is roughly 15-18ng/ml (=37,5-45 nmol/l). When referred to values presented above, this can already be considered as serious deficiency. Some estimation says that 40-60% of global population is at risk for vitamin D deficiency.

There are two ways to receive proper amounts of vitamin D; vitamin D supplementation and sun (UVB) exposure. Sun exposure should be the number one method of choice. Studies have revealed that large quantities of vitamin D are formed in the skin in response to full-body summer sun exposure. There are couple rule of thumbs to remember when getting your vitamin D trough sun exposure:

– exposure to the sun should be midday between 10am-2pm- person with white skin will need around 15 minutes of full body sun exposure whereas those with darker skin will need longer exposure- sun exposure after the point where your skin starts turning red does not anymore increase your skin’s vitamin D production, because when equilibrium is reached in the skin the excess vitamin D is degraded by ultraviolet light- sunburns have no health benefits- you are not making much vitamin D if your shadow is longer than you are – occasional sunlight exposure of your face and hands is not sufficient for vitamin D nutrition- if you are living on latitude above 30 degrees north or below 30 degrees south you will more than likely need vitamin D supplementation from September to mid-AprilIf you get your vitamin D from the sun it is not necessary to test your vitamin D levels. This is because your body can not overdose on vitamin D created trough sun exposure. However if you take vitamin D in supplement form you should always be checked that you are taking the correct dose. Testing of vitamin D levels is best to be done after a few weeks from starting the supplementation.

The potency of vitamin D is measured in International Units (IU), one IU equaling to 0.000025 milligrams (mg). Also micrograms (mcg or µg) are commonly used, 40IU equaling to one microgram. Depending of country you live in, the official recommendations for vitamin D intake are usually somewhere between 400 to 1000 IU per day. While these amounts are enough to maintain decent bone health and normal calcium metabolism in healthy people, they are found to be insufficient to raise and maintain the vitamin D levels that are needed for proper health. To function properly a healthy human body utilizes roughly 4000 IU of vitamin D per day. Thus the appropriate dose of vitamin D for a healthy adult would be closer to 4000-5000 IU per day. As an example, Vitamin D Council is recommending following amounts of supplemental vitamin D3 per day, in the absence of proper sun exposure.

– 1000 IU for healthy children under the age of 1 years- 1000 IU per every 25lbs (11,3kg) of body weight for healthy children over the age of 1 years- at least 5000 IU for healthy adults and adolescents- at least 6000 IU for pregnant and lactating mothersBy optimizing your vitamin D levels you can help to prevent not only colds and flu, but all kinds of diseases, and maintain good health altogether. Sunlight should your number one source for vitamin D but it is crucial to avoid sunburn. Before taking vitamin D supplementation it is wise to get your vitamin D level tested, preferably with nutritionally oriented physician.

Richardson Cancer Diet by Dr. Janet Hull
A natural effective cancer diet for people with cancer or for the prevention of cancer.
Richardson Cancer Diet by Dr. Janet Hull