Low Vitamin D: A Global Concern

Recent studies suggest that vitamin D is much more important in fighting off disease than previously thought. Being deficient in this vitamin puts one at risk of diseases such as cancer, osteoporosis, and multiple sclerosis. Chances are that if you live in a northerly geographic region you do not get enough vitamin D. Persons who live a rather sedentary lifestyle and do not get outside for at least a 15-minute daily walk in the sun are in the same position. Latinos, African-Americans and others with dark skin tend to have much lower levels of vitamin D, as do people who are overweight or obese. All around the world millions of persons suffer from vitamin D deficiency. This phenomenon is so common that it affects persons on every continent, of all ethnic groups, and across all ages. Some surveys suggest that perhaps half of the world’s population has inadequate blood levels of vitamin D. Sadly, physicians, even in industrialized countries, are seeing the resurgence of rickets, the bone-weakening disease that had been largely eradicated through vitamin D fortification.

As with most research findings, there is plenty of debate. Indeed, as opposed to what many people think, there are few certainties in science; its nature is to be open to criticism, discussion, and revision. The Institute of Medicine (IOM) released a report in November 2010 which recommends a daily vitamin D intake of 600 IU per day, for people ages 1 to 70, and 800 IU, for people over age 70—the report referred to persons living in the U.S. and Canada. The report also recognized the safety of vitamin D by increasing the upper limit from 2,000 to 4,000 IU per day, and acknowledged that even at 4,000 IU per day, there was no good evidence of harm.

Some in the scientific community believe the new guidelines are too conservative about the intake, and that they do not give due consideration to the latest findings about vitamin D and health. They contend that the new guidelines are not enough to prevent chronic disease, and they are not sufficient to help those who have problems with their bones. This is an important debate, and in order to understand it better it is necessary to know the origins of vitamin D and how it functions in the human body.

Vitamin D Sources and Function

Our body makes vitamin D and it is also a nutrient we eat. The body produces vitamin D from cholesterol, which itself is triggered by sun lighting on the skin. Yet many persons do not make enough vitamin D from the sun, persons with darker skin, those who are overweight, and persons who use products that block sunlight being among them. Correctly applied sunscreen reduces our ability to absorb vitamin D by more than 90 percent.

To be sure, not all sunlight is of the same quality and intensity: The sun’s ultraviolet B (UVB) rays—the so-called “tanning” rays, and the rays that trigger the skin to produce vitamin D—are stronger near the equator and weaker at higher latitudes. Indeed, persons who live in places prone to considerable cloudiness and rain can suffer from vitamin D deficiency. The other way we get vitamin D is to eat food that contains a lot of it. However, few foods are naturally rich in vitamin D, so the biggest dietary sources of vitamin D are fortified foods and vitamins supplements.

Vitamin D helps the body absorb and retains calcium and phosphorus, which are critical elements for building bone. Laboratory studies show that vitamin D can reduce cancer cell growth, can increase muscle strength, and can help control infections. There may yet be other functions for vitamin D, and scientists continue to explore the many other uses for this important substance.

New Vitamin D Research: Beyond Building Bones

Vitamin D research has proved to be of considerable fecundity. Although there have been many reports issued over the years, there are only a few that offer enough evidence to constitute a clear medical breakthrough. Here we provide the more promising areas of vitamin D research, highlighting the complex role of vitamin D in disease prevention—and the many unanswered questions that remain.

Vitamin D and Bone and Muscle Strength

A number of random trials have shown that high doses of vitamin D supplements help reduce bone fractures. A summary of the evidence comes from a combined analysis of 12 fracture prevention trials that included more than 40,000 elderly people, most of them women. Researchers found that high intakes of vitamin D supplements—of about 800 IU per day—reduced hip and non-spine fractures by over 20 percent, while lower intakes (400 IU or less) failed to offer any fracture prevention benefit.

It has been shown that vitamin D may also help increase muscle strength, which can help prevent elderly persons from falling, a common problem that leads to increased rates of disability and death among them. A combined meta-analysis found that taking 700 to 1,000 IU of vitamin D per day lowered the risk of falls by 19 percent; the combined studies also show that taking 200 to 600 IU per day offered no such protection. Based on this data, the International Osteoporosis Foundation recommends that adults over age 60 maintain vitamin D blood levels of 30ng/ml. This means that most people will need vitamin D supplements of at least 800 to 1,000 IU per day, and possibly higher, to reach these levels.

Vitamin D and Heart Disease

The heart, as a skeletal muscle, is a receptor of vitamin D. A number of studies have found that lack of vitamin D is linked to heart disease. The Health Professional Follow-Up Study observed the vitamin D blood levels in nearly 50,000 men who were healthy. They followed the same group for 10 years and found that men who were low in vitamin D were twice as likely to have a heart attack as men who had adequate levels of vitamin D. Other studies have linked low vitamin D levels to an increased of heart failure, sudden cardiac death, stroke, overall cardiovascular disease, and cardiovascular death. There is some evidence that vitamin D plays a vital role in controlling blood pressure and preventing artery damage. This goes some ways in explaining the findings above. However, more research is needed before a sounder conclusion can be made.

Vitamin D and Cancer

Nearly 30 years ago, researchers discovered an interesting correlation between colon cancer deaths and geographic location. They found that people who lived at higher latitudes, such as in the northern U.S. or Canada, had higher rates of death from colon cancer than people who lived closer to the equator. The sun’s UVB rays are weaker at higher latitudes, and in turn, people’s vitamin D levels in these high latitude locales tend to be lower. Researchers formed the hypothesis that vitamin D deficiency can lead to an increased risk for getting colon cancer

Some time has passed, but dozens of studies suggest a relationship does exist between low vitamin D levels and increased risks of colon and other cancers. The evidence is strongest for colorectal cancer, with observational studies have found that persons with lower vitamin D levels are at higher risk of getting such diseases. Vitamin D levels may also predict cancer survival, but there is as yet little evidence to support this. However, it is not yet certain that taking vitamin D supplements necessarily lowers the risk of contracting cancer. This latter idea will be tested in the VITAL trial. The VITAL trial will look specifically at whether vitamin D supplements lower cancer risk. However, it is likely to be years before the trial produces any results. Additionally, the VITAL trial could fail to detect a real benefit of vitamin D. There are several reasons for this. First, if people in the placebo group decide to take their own vitamin D supplements, the differences between the placebo group and the supplement group could be minimized. Second, the study may not follow participants for a long enough time to show a cancer prevention benefit; or study participants may be starting supplements too late in life to lower their cancer risk.

In any case, given the evidence now on hand, 16 scientists have circulated a “call for action” on vitamin D and cancer prevention. Given the high rates of vitamin D inadequacy in North America, the strong evidence for reduction of osteoporosis and fractures, the potential cancer-fighting benefits of vitamin D, and the low risk of vitamin D supplementation, these scientists recommend vitamin D supplementation of 2,000 IU per day. The Canadian Cancer Society has also recommended that Canadian adults consider taking vitamin D supplements of 1,000 IU per day during the fall and winter. They also recommend that people who are at high risk of having low vitamin D levels because of old age, dark skin, or geographic location take vitamin D supplements year round.

Reducing your risk of Type 2 diabetes?

Is it possible to prevent Type 2 diabetes?

If you know that you are prone to diabetes because, for example, you have a family history of Type 2 diabetes or you had diabetes during pregnancy, making lifestyle changes can help you delay or even prevent its onset. These changes include eating more healthily, becoming more active, and losing weight if you need to. Stopping smoking and drinking less alcohol do not affect whether or not you will develop diabetes, but they will help reduce your risk of developing heart disease.

How does keeping to the correct weight for my height help?

Your body will be able to handle glucose and use insulin as efficiently as possible. If you are overweight, your resistance to insulin increases.

Why is it important to stay physically active?

Physical activity helps you maintain your weight in the correct range for your height or to lose weight if you need to. It also increases your body’s efficiency at storing and using glucose. Furthermore, activity keeps your heart and blood vessels healthy – this is very important if you are at risk of developing diabetes.

Could I lose weight by changing my eating habits without doing more physical exercise?

Yes, eating less is the key to losing weight. However, activity can go a long way to help. For example, you can burn off excess calories thorough exercise. Reducing your calorie intake and using more energy than you take in will facilitate weight loss.

I am 50 and have been overweight for most of my adult life. Will losing weight now help me prevent diabetes?.

If you are overweight, losing weight will always improve your health, regardless of how old you are. There is no guarantee of preventing Type 2 diabetes, but being the correct weight for your height will greatly reduce your risk and will be of benefit if you do develop Type 2 diabetes

I’ve always been slim. Will this naturally protect me from Type 2 diabetes?

Being the correct weight for your height is an important part of reducing your risk of Type 2 diabetes. However, body shape is also important; carrying extra fat around your waist rather than your hips increases the risk of diabetes. Checking your body mass index and waist size will help you find out whether your weight and body shape are risk factors.

There is a lot of diabetes in my family and we tend to be overweight. I want to protect my teenagers from diabetes but they eat a lot of junk food. What can I do?

Your children are at risk of Type 2 diabetes due to your family history, and their risk increases if they become overweight (too much junk food can cause weight gain, especially if your children are not very active). Teach them about Type 2 diabetes and the role that high-calorie, high-fat, and junk food plays in weight gain. Including your children in the shopping for and preparation of food, adapting recipes, and helping them learn about food labeling may also help.

I am in my 60s and have Type 2 diabetes. How can I help my young grandchildren avoid developing it?

Encouraging healthy eating habits by offering meals and snacks that are low in fat, salt, and sugar (reserving candy and chocolate for special treats) will help reduce their risk. You could also encourage them to walk rather than being driven short distances, or play active games rather than sit in front of a computer or television.

Type 2 Diabetes and young people

Can children and teenagers develop Type 2 diabetes?

Yes; although traditionally Type 2 diabetes has affected only older people, with the increased tendency for children and teenagers to be overweight and less active, the incidence of Type 2 diabetes in this age group has increased dramatically in recent years, especially in North America and northern Europe.

How many young people are there with Type 2 diabetes?

It is estimated that there may be approximately 500,000 children in the US with the condition. Children born today have a greatly increased risk of Type 2 diabetes and heart disease because of obesity and inactivity. It is likely that nearly half of all people diagnosed with Type 2 diabetes in the next 15 years will be young people

Is Type 2 diabetes more or less serious if you develop it when you are young?

The condition is equally serious at whatever age it develops. However, the complications of diabetes are associated with the length of time you have it. So if you develop diabetes at a younger age, you are at greater risk of heart disease and the other complications of diabetes, such as eye, kidney, and nerve damage.

Do children grow out of Type 2 diabetes?

You cannot grow out of or be cured of diabetes. However, the risk of long-term problems associated with it can be greatly reduced by losing weight, if necessary, and being more active. These changes can make you better able to use the insulin that you produce naturally.

What’s the best way to treat Type 2 diabetes in children and young people?

The ideal way is to help them lose weight by encouraging healthy eating and more physical activity. If these habits become a normal part of a child’s lifestyle, they may delay the need for pills and insulin injections and make any prescribed medication as effective as possible.

My 20-year-old daughter has been diagnosed with Type 2 diabetes. What restrictions will she have on her life?

She will always need to look after her diabetes on a day-to-day basis, which she can do by eating healthily, staying active, and taking any medication she is prescribed. However, she won’t be restricted in what she can do, unless she wants to purse one of the few careers that have specific rules relating to people with diabetes.

What is MODY?

MODY stands for “maturity onset diabetes of the young”, a rare type of diabetes that affects about 1 in 100 people with diabetes. It usually appears in your teens or 20s and is similar to Type 2 diabetes in that your treatment focuses on healthy eating and physical activity first, then pill treatment and/or insulin if necessary. There are different forms of MODY, which might affect your risk of complications occurring, so having a genetic test is important.

I have had diabetes, which I treat with pills, since I was 19. How do I know whether it is MODY or Type 2 diabetes?

MODY develops only in people with specific genes that cause a defect in the way the insulin-producing cells in your pancreas work. This leads to your producing less insulin. MODY can be confirmed by genetic testing. If several members of your family also developed diabetes at a young age, you can have the genetic test that will tell you what type of diabetes you have.

Who gets Type 2 Diabetes?

Can you be born with Type 2 diabetes?

No. type 2 diabetes is a condition that develops over time. It is most common in people over the age of 40, but there are increasing numbers of children and teenagers who are developing Type 2 diabetes, especially those who are overweight and inactive.

What are my chances of getting Type 2 diabetes if one or both of my parents has it?

If one of your parents has Type 2 diabetes, you are at a slightly increased risk of developing it; if both of your parents have it, your risk is much greater. If you have a family history of diabetes, you can do a lot to reduce your risk by keeping your weight in the normal range and becoming more active if you need do.

My sister has been diagnosed with Type 2 diabetes. Should I be tested for it?

If you have a brother or sister with Type 2 diabetes you have an increased risk of developing the condition. If you have an identical twin sister or brother who has Type 2 diabetes, you have a very high chance of developing it. Having a blood test will reveal whether you have Type 2 diabetes. If you find you don’t have diabetes, you can take steps to reduce your risk of developing it in the future.

I am overweight. Does this mean I will get diabetes?

Not necessary, but being overweight can reduce your body’s ability to regulate glucose levels, which in turn can lead to Type 2 diabetes. You can dramatically decrease your risk of Type 2 diabetes by losing weight. How your weight is distributed is also important. Carrying extra fat around your waist rather than your hips is linked with Type 2 diabetes.

Is it true that ethnic background is a risk factor for Type 2 diabetes?

Yes, if you are of Mexican or Hispanic, African-American, or American Indian descent, you are two to three times more likely to develop Type 2 diabetes than if you are of Caucasian origin.

I gave birth to large babies but didn’t have gestational diabetes. Does this mean I won’t get Type 2 diabetes?

One reason that babies grow very large is because they have to make more insulin to deal with extra glucose coming through the placenta. Even though you weren’t diagnosed with gestational diabetes, finding out if any tests revealed an increased glucose level will help you and your health professional asses your level of risk of Type 2 diabetes in the future.

Risk Factors for Developing Type 2 diabetes

Your chances of developing Type 2 diabetes depend on a number of different factors, including your family background, your weight and body shape, and how much physical activity you get.

Lower risk
• Few or only one family member with diabetes
• Caucasian
• No previous gestational diabetes (diabetes that develops in pregnancy)
• Fairly active
• Normal weight for height

Higher risk
• Many family members with diabetes
• Mexican/Hispanic, African-American, or American Indian
• Gestational diabetes in the past
• Very little activity every day
• Overweight, especially around the waist

Weight Control Puzzle

Not only is weight control difficult, it’s not even fair. We are different in genetic makeup, age, gender, physical activity, medical problems and emotional health.

Heredity and Environment
If members of your family are overweight (10-19 percent over ideal weight) or obese (20 percent or more over ideal weight), you are 20-30 percent more likely to become overweight or obese than someone who does not have a family history of weight problems. If a mother is heavy, there is a 75 percent chance that her children will be heavy. If she’s thin, her children are likely to be thin, also.

Genetics is a factor, but the biggest health risk is that people use it as an excuse to deal with the problem. Other people have predispositions to diabetes, cancer or heart disease, but that doesn’t mean they shouldn’t do everything they can to prevent or delay the onset of a family problem.

Research is finding out that genetics is playing a bigger role than we thought. Studies of identical twins who grew up in separate places have shown great similarities in body shape and weight. Our body shapes (round, angular or athletic) can reflect our capacities to store fat. There is also evidence that people burn calories at different rates, but again, this should not be used as an excuse.

Even though there may be some metabolic predisposition to being overweight, environmental factors are just as important. Some people have just learned to eat too much. Studies comparing portion sizes show that Americans put a lot more food on their plates than Europeans and the sizes in the United States are getting bigger.

Doctor believes that obesity is determined partly by genes (30 percent) and the rest by environment (70 percent). People’s genes haven’t changed since 1930, but now more people are fat. We eat more food, more fat, more sugar, and we don’t exercise.

Age
As we get older, the amount of lean muscle tissue decreases. That makes fat account for a greater percentage of total weight. At the same time, our rates of metabolism slow down with age. These factors can combine to add pounds, and, if the person also reduces the amount of exercise, the three changes make weight gain likely.

Gender
Men have more muscle tissue than women, while women have comparatively more fat tissue than men. Because of those differences and because men have a higher resting metabolic rate than women, men may expend 10 percent to 20 percent more calories than women at rest. Women may have to exercise longer and harder than men to lose the same amount of weight.

Exercise
Nutrition experts emphasize the importance of exercise and its relationship to being overweight. Inactivity does not always cause obesity, but overweight people are less likely to be physically active than people of normal body weight. Which problem comes first is not clear. The effect of exercise is an individual consideration, but it is still a vital component of a total weight control program. Even if a person knows that exercise is necessary, he or she may need further education, physical skills or simply enough time to participate in a program.

Health Problems
Although health problems are frequently blamed for being overweight, the truth is that less than five percent of all obesity is related to metabolic or hormonal imbalances.

Discipline
With all of the talk about genetics, body types and family history, does will power have anything to do with weight control? Yes, people exhibit discipline in all sorts of physical behaviors — exercising, resting, refusing to use drugs, abstaining from alcohol. Overeating is no different. We may have individual needs, but the ability to show nutritional discipline is another part of the weight control puzzle.

Understanding Diabetes

What is Type 2 diabetes?

Type 2 diabetes is the most common type of diabetes and used to be called “maturity onset” or “non-insulin-dependent” diabetes. When you have diabetes your body cannot use glucose (your body’s main source of energy) in the usual way. Normally, glucose is absorbed by your body cells and burned as fuel. In Type 2 diabetes, glucose stays in your bloodstream either because your natural supply of insulin – a hormone that regulates the level of glucose in your blood – is not working properly or your body is not making enough of it. A raised blood glucose level can give you a range of symptoms including intense thirst and frequent urination. You are also much more prone to heart and circulatory problems because it is one part of a syndrome or collection of conditions, known medically as the metabolic syndrome, that causes high blood pressure and high blood fat levels. A high blood glucose level, without treatment, can damage your kidneys, nerves, and eyes. However, you can do a great deal to reduce the risk of these complications.

What is the difference between Type 1 and Type 2 diabetes?

People with Type 1 diabetes usually develop severe symptoms over a short time in childhood or early adulthood and their bodies cannot absorb any glucose without the help of a continuous supply of insulin either by injection every day or by an infusion of insulin through a pump. People who are prone to Type 1 diabetes have a specific genetic makeup that causes their bodies to destroy some of their own cells.

Is Type 2 less serious than Type 1 diabetes?

Definitely not. In some ways, Type 2 diabetes is a more serious condition than Type 1 because you could have it for a number of years before you are diagnosed. Consequently, you could already have developed some of the long-term complications of diabetes without being aware of them. In particular, Type 2 diabetes is linked with heart disease because of its association with high blood pressure and high cholesterol levels. These cause progressive thickening of your arteries over years that reduces your blood flow and increases the likelihood of a heart attack or stroke. Being overweight, particularly if you carry surplus weight around your waist, makes the risk of heart disease even greater.

Why does Type 2 diabetes develop?

There is no single reason why you develop Type 2 diabetes. A combination of factors affects how likely you are to develop the condition. Being overweight and inactive are two major factors that increase your risk of developing Type 2 diabetes. Other factors that put you at a higher risk include a family history of diabetes and being a member of certain ethnic groups, such as African-American, Hispanic, or American Indian.

How common is Type 2 diabetes?

About 130 million people worldwide have Type 2 diabetes, and this number is increasing each year. In the US, more than 17 million people are known to have diabetes. About 90-95 percent of these have Type 2 diabetes. There are also many people who have Type 2 diabetes but have not yet been diagnosed with the condition.

Why is Type 2 diabetes becoming more common?

Today, people are much less active in their daily lives than those of previous generations. Therefore, they are more likely to be overweight or obese, which, in turn, increases the risk of developing Type 2 diabetes. More children and teenagers are developing Type 2 diabetes for this reason.

What does insulin do in my body?

Insulin is a hormone (body chemical) that is made and released by your pancreas, which lies behind your stomach. Insulin acts like a key to let glucose (which comes from carbohydrate foods) move from your bloodstream into your cells, where it is used to produce energy. Your body normally produces more insulin immediately and for some time after a meal, when there is more glucose around, and less at other times. Another hormone called glucagon (also produced by your pancreas) prevents insulin from letting your blood glucose level drop too low.

What would my blood glucose level be if I didn’t have diabetes?

If you didn’t have diabetes, your insulin and glucagon would keep your blood glucose level within a narrow range (75-130 milligrams of glucose per deciliter (mg/dL) of blood). As a result, whether you eat a lot of carbohydrate or only a little, your body has the constant supply of energy it needs to work properly.

How high can blood glucose rise in someone with Type 2 diabetes?

Very rarely, a blood glucose level of up to 1,800 mg/dl can be recorded when you are first diagnosed with diabetes. The most common situations is for your blood glucose to reach a level of 180-360 mg/dl – at which stage your symptoms would lead to you being diagnosed.

What goes wrong in Type 2 diabetes?

Because your body doesn’t produce enough insulin, produces it more slowly, and/or your cells are resistant to the action of insulin, your blood glucose cannot be as finely regulated as it would be normally. As a result, it is difficult for glucose to pass into your cells to be burned for energy, so it builds up in your blood.

What does insulin resistance mean?

This term means that, even if you still produce insulin, your body cannot use it in the normal way to let glucose into your cells. Insulin resistance is linked to being overweight and being physically inactive. If you have Type 2 diabetes, you are also more likely to have high blood pressure and elevated cholesterol levels.

Howe can I tell if I have Type 2 diabetes?

You may not have any symptoms, in which case your diabetes might only be found at a routine medical or eye test. Many of the symptoms you might experience can be part of growing older – for example, feeling tired, or getting up at night to urinate – and you may not think you have diabetes, particularly if these symptoms are mild.

Will I have to inject myself with insulin every day?

Controlling your weight, eating healthily, and keeping or becoming physically active may keep your blood glucose level in the recommended range without any medication, sometimes for a short time or, in some cases, for years. If your blood glucose is regularly too high, despite your best efforts, you will be prescribed pills and, eventually, you are likely to need insulin injections.