Why Vitamin D is vital, explains leading expert

The winter is finally here! The weather is colder and the sun sets before most of us even leave the office. How do you know if you are getting enough vitamin D and how much should you consume?


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Dr John Cuomo, Executive Director of Research and Development at USANA Health Sciences answers important questions on why this vitamin is so important to the optimum functioning of the human body:


What are the main functions of vitamin D in the body?


Vitamin D appears to have many functions in the body.  Every cell, regardless of where it is located has a vitamin D receptor.  This would indicate that vitamin D has multiple functions and the scientific evidence backs this up.  The best documentation of the importance of vitamin D is in bone health. Absorption and utilization of calcium appears to be a vitamin D controlled process. Other minerals including magnesium, boron and silicon may also depend on vitamin D to be absorbed and deposited into the bone matrix.  The RDA data for vitamin D is based solely on the function for uptake and utilization of minerals for bone health.  So while bone health, and prevention of osteoporosis is an extremely important function of vitamin D, it is part of what makes vitamin D important to your health.  There are numerous studies showing that Vitamin D is also essential for overall immune system function and for muscle strength.  Epidemiological studies also show links to glucose metabolism, cell proliferation, osteoporosis, osteomalacia, impaired muscle function, infection, autoimmune disorders, diabetes, some cancers and CVD.


What are the best natural sources?


One of the best ways to get vitamin D is to expose your skin to sunlight.  15  to 30 minutes of sun exposure between the peak hours of 10am-2pm will make thousands of IU of vitamin D. Just be careful not to burn.  Dietary sources are lower.  Some product such as milk and orange juice are fortified with vitamin D, but the dose is usually low and the form is different than from sun exposure.  Some fish also have vitamin D but the amounts vary significantly.


-Is the vitamin D in milk etc a chemically made version and, if so, does it differ (like vitamin e) from the natural source? 


The story here is a little different than for vitamin E.  The form of vitamin D produced in skin naturally from sunlight is cholecalciferol or vitamin D3.  This is also the form used in most nutritiona
l supplements like USANA Vitamin D tablets.  Milk is fortified with vitamin D2 or ergocalciferol.  While it is naturally derived, it is not the same as the D3 that we produce naturally from sun exposure.  In addition there are several clinical studies on supplementation with D2 vs. D3, and it looks like D3 is more bioavailable, and a better choice.


What are the best ways to take vitamin D to ensure you’ve taken enough?


Dietary sources are not sufficient.  Even though milk, orange juice and fish do contain vitamin D, all of the data we have seen indicates that the vast majority of Americans are vitamin D deficient.  The two best ways to get the vitamin D you need are to get adequate sun exposure to exposed skin (without sun block) or to take a good vitamin D supplement.  In addition, the only good way to tell if you have adequate stores of vitamin D is to have a blood test run.  If your doctor asks for this test, be sure they measure the amount of 25-hydroxy vitamin D in plasma, and the amount should be 40 – 60 ng/mL.


Does sunscreen stop us absorbing vitamin D?


Yes. To make vitamin D in the skin, UV light must hit the skin directly.  Sunscreen effectively blocks this, and almost no vitamin D will be produced if you apply sunscreen.


-How often should vitamin D be taken?


A daily supplement of 200 to 500

IU of vitamin D.


Why is vitamin D important?


It supports healthy bones, immune function, muscle strength, glucose control, and may help prevent auto immune disease and heart disease.



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Are you getting enough Vitamin D?


As a lack of vitamin D is linked to various diseases including the return of rickets, cancer, heart disease, tuberculosis and diabetes.

Since it is produced in the skin on exposure to sunlight, those living in Scotland and the North of England are more likely to suffer deficiency.

Experts recommend between five and 25 micrograms per day, however, 90 per cent of adults in the UK make less than three.

The situation is worst for those north of Birmingham where the sun is too weak in winter for the vitamin to be produced.

A recent report in the US journal Proceedings of the National Academy of Sciences revealed that people with higher levels were more likely to survive colon, breast and lung cancer. This follows last year’s University of San Diego review of 40 years of research, which revealed that a daily dose could halve the risk of breast and bowel cancer.

Other claims are that it reduces the risk of heart disease (a study of 10,000 women in California found that those who took supplements had a 31 per cent lower risk of dying from it), diabetes (in a Finnish study of 12,000 children, it cut their chance of developing Type A diabetes by 80 per cent), even colds and flu (New Yorkers who took vitamin D had flu 70 per cent less often).

Yet despite this increasingly compelling evidence, too many of us are not getting enough. The result: a resurgence in rickets, which stunts growth and deforms the skeleton, causing bowed legs.

Vitamin D Fact File

• 90 per cent of the body’s supply of vitamin D is generated by reaction to sunlight on the skin.

• Vitamin D is found in oily fish like sardines, salmon, mackerel and tuna, cod liver oil, and in milk, cheese, eggs and liver.

• “Healthy Start” supplements for children up to the age of four are given free to those on benefits but can also be bought for £1.70 at pharmacies or health clinics.

• The first mention of rickets is credited to Daniel Whistler, an English doctor who wrote a paper in 1645 on the subject.

• Vitamin D was named in 1922 by the American biochemist Elmer McCollum, who performed experiments to find the nutrients within cod liver oil. It was so called because it was the fourth substance he identified.

• One in 100 children from ethnic minorities in this country is thought to be deficient in vitamin D; darker skin requires more sun to produce the vitamin.

• In 2003 a New York couple were convicted of endangering the life of their 15-month-old baby after subjecting her to a strict vegan diet which left her suffering from rickets. Silva and Joseph Swinton were sentenced to six and five years in jail.

• The classic signs of rickets are bow legs caused by softening of the bones; if not detected early surgery is needed to correct it.

• Most people can make enough vitamin D in the summer to last them through the winter

Can vitamin B1 help diabetics?

London: The vitamin B1 is excreted faster in diabetics than in healthy people, according to a new study by the Warwick Medical School.

Vitamin B1, also called thiamine, is important in keeping the body’s circulatory system healthy but is dispelled by diabetics 15 times more quickly than in healthy people.

This deficiency could increase the chance of heart attacks and strokes, which account for around 80 per cent of diabetes deaths.

The discovery may mean that high-dose vitamin B1 supplements could therefore reduce the risk of patients developing heart problems. Another option would be to develop drugs to stop the kidneys getting rid of so much of the vitamin. The study, published in the journal Diabetologia, involved 74 diabetics and 20 healthy volunteers.

Thiamine concentration in the blood was 76 per cent lower in Type 1 diabetics and 75 per cent lower in Type 2 diabetics.

Lack of thiamine is believed to increase the risk of heart problems because it affects the working of special cells which line the body’s circulatory system.

Professor Paul Thornalley, who led the study, is now running a trial to test whether patients given extra doses of the vitamin have healthier hearts.

He is giving patients a tablet containing 300milligrams of vitamin B1 a day. The average daily nutritional intake of vitamin-By Daniel Martin

Health Reporter B1 is 1mg – meaning changes to diet would not be enough to have an effect.

Matt Hunt, science information manager at the charity Diabetes UK, which funded the study, said it could lead to ‘very exciting outcomes’.

He added: ‘Researchers are already looking into the effect of giving people the vitamin in tablet form to see if early kidney damage can be reversed.

‘From there, work could be done to see what effect supplementing vitamin B1 levels could have on other complications of diabetes such as nerve and eye damage.’

More than 1.9million Britons are Type 2 diabetic and up to 750,000 more are undiagnosed. Type 2 is linked to obesity and up to half of cases could be prevented through changes to diet and exercise.

Around 300,000 Britons are Type 1 diabetic, which is present from childhood.

Folic acid may protect against Alzheimer’s

New York: Folic acid may lower the risk of Alzheimer’s, say US doctors.

The finding follows a study of nearly 1,000 elderly people which discovered that those with higher levels of this B vitamin were less likely to suffer mental deterioration.

The research was carried out by Columbia Univesity Medical Center spent six years examinng the diet of 965 healthy adults with the average age of 75. The one in five who went on to develop Alzheimer’s had the lowest levels of folic acid.

Folic acid has also been found to be useful in improving the memory of people aged over 50.

Folic acid, a B vitamin is found mostly in dark green vegetables such as asparagus but is easily destroyed by cooking. Supplements provide a form of the vitamin more easily taken up by the body. And the researchers recommended that both natural and supplement forms of the vitamin were the best choice for older people.

Vitamin C improves heart function

Tokyo: Vitamin C can improve heart function during exercise in patients who have suffered a heart attack, according to a report in the International Journal of Cardiology.

The vitamin improves the efficiency of the sympathetic nervous system, which is part of the nervous system that controls heart rate and other involuntary body responses. Heart disease can cause the sympathetic function to deteriorate.

Dr. Kazuyo Kato and other colleagues from Nippon Medical School, Tokyo, investigated whether ascorbic acid influenced the sympathetic response to exercise in 21 men who were studied at least one month after a myocardial infarction. The participants underwent symptom-limited exercise testing twice, once 2 hours after oral administration of 2 grams of ascorbic acid and once without the supplement.

Although resting blood pressure and heart rate did not differ with or without ascorbic acid, the authors report, the heart rate response to peak exercise was significantly higher, an indication of better heart function, after ascorbic acid than without ascorbic acid.

Ascorbic acid administration also improved heart rate increases from rest to peak exercise, as well as the peak oxygen consumption, the results indicate.

“These data suggest that an antioxidant vitamin such as ascorbic acid can effect a recovery of the sympathetic dysfunction caused by injury through excessive oxidative stress and improve exercise intolerance,” Dr. Kato and colleagues conclude.

“Further studies are needed to determine whether long-term ascorbic acid administration will improve sympathetic nerve dysfunction in patients and whether other antioxidants would