Vitamin D Everything You Need to Know


What Is Vitamin D

If you’re not getting the right vitamins, your diet will fail. If your diet is wrong, your physique will fail. It’s simple. Get your vitamin D. Here’s why.

According to the American Journal of Clinical Nutrition, worldwide vitamin D deficiency has reached pandemic proportions. A study found that about 77% of Americans having inadequate stores of this vitamin.

People who live in the Northern Hemisphere, mainly at 40 degrees latitude and higher, get less sunlight during the fall and winter months. As not everyone’s schedule permits daily sunbathing, it becomes even more, vital to get ample vitamin D from our diets. Since less this vitamin is made in darker-skinned people than in those with lighter skin, it’s estimated that about 97% of non-Hispanic black people and 90% of Mexican-Americans are deficient in this vitamin.

Dietary vitamin D is found in fortified foods and supplements and a small amount of foods that have them in a naturally occurring form. Achieving adequate vitamin D stores is tough for those living at high latitudes because of the scarcity of naturally this vitamin rich foods. Still, it’s an important vitamin for optimal health and quality of life.

What Is Vitamin D?

This vitamin is also known as calciferol. It’s more correctly defined as a prohormone, a precursor substance that the body converts to its active hormonal form. This is needed for the absorption of calcium from the intestines, which reduces the mineral’s loss from the body through urinary excretion.

Without enough vitamin D stores, the intestines can absorb no more than 10 to 15% of dietary calcium. It’s also vital in the body’s digestion of phosphorus, an essential mineral needed in bone formation.

It also assists the body’s natural processes through its involvement in blood cell formation, cell reproduction, glucose regulation and immune system enhancement. It’s an essential nutrient to the body, enabling it to produce over 200 antimicrobial peptides that are vital to warding off infections.

Why Are So Many Of Us Lacking?

The main reason so many are vitamin D deficient is too little exposure to sunlight. The sun can be your best friend. Why? Sun exposure is needed to irradiate a cholesterol compound in the skin that’s transformed by enzymatic action into the active form of vitamin D hormone, calcitriol.


Sun exposure is needed to irradiate a cholesterol compound in the skin that’s transformed by enzymatic action into the active form of this vitaminhormone, calcitriol.

Calcitriol is in charge of regulating calcium absorption and bone development. Since the average American covers about 95% of their skin with clothes, wears sunscreen on sunny days and spends less time in the sun than in the past, our vitamin D stores are much less than those of our ancestors.

How Much Is Enough?

The daily recommended intake of vitamin D is 600 IU for those up to the age of 70. It’s boosted to 800 IU per day for those over 70. The American Academy of Pediatrics recommends that infants get at least 400 IU of vitamin D per day. This is to prevent the crippling disease rickets, which causes bone malformation. Other diseases connected with this vitamin deficiency include cancer, coronary heart disease, type-1 diabetes, multiple sclerosis, Crohn’s disease and rheumatoid arthritis.

As vitamin D affects the expression of about 10% of the body’s genes, its levels can have a major impact on one’s disposition to some diseases and cancers. Some studies show that optimal vitamin D levels cut the risk of some cancers by 60%. Because of calcitriol’s ability to regulate the rate of calcium and phosphorus resorption from bone, it’s been used in a clinical setting to cut the risk of osteoporosis.

Vitamin D

Vitamin D Deficiency?

There are many symptoms of this vitamin deficiency. The most common are feelings of tiredness, general aches and pains and frequent infections. Other symptoms include muscle cramps, constipation or diarrhea, weight gain, restless sleep, poor concentration, high blood pressure, headaches and bladder problems.

Clinicians tend to test patients for hypovitaminosis D when they show musculoskeletal symptoms such as bone pain or muscle weakness. These symptoms are often misdiagnosed as age-related weakness, chronic fatigue, fibromyalgia and even depression.

Deficiency Symptoms

There are many reasons for vitamin D deficiency. The number one cause is generally accepted as underexposure to the sun’s rays. The sun is our main source of vitamin D3. This is the form that boosts levels of dopamine and serotonin in the brain to produce a feel-good feeling.

Poor dietary intake is also a root cause.

How can that happen?

Simple. The list of foods naturally rich in vitamin D is quite short. It includes salmon, tuna, mackerel, cod, oysters, shrimp, beef liver and eggs. If you don’t like fish, you’re in tough.

Your age can also affect your vitamin D status. As we age, our kidneys become less able to convert vitamin D into the active hormonal form, calcitriol. If you’re overweight, have gastrointestinal (GI) disorders or older, you’re at an increased risk of being deficient. As this vitamin is a fat-soluble vitamin, the parent compound, cholecalciferol, gets trapped within the fatty adipose tissue of overweight people.

How Does Working Out Affects Levels?

People with more muscle mass need more vitamin D. Physical inactivity has also been shown to link with low vitamin D levels. In a study of people aged 55 to 74 in the U.S., those with low levels of physical activity, diets low in calcium and bad body mass index readings were generally found to have low vitamin D status.

While three or more hours a week of intense exercise—such as playing sports or jogging—has been found to reduce heart attack risk by 22%, it’s also been shown to boost vitamin D and healthy cholesterol levels. This is due largely to the fact that people who exercise more tend to spend more time outside.

Health Disorders Are Also Triggers

People with health disorders affecting GI function, such as celiac disease, are also at risk for vitamin D deficiency. About 64% of men and 71% of women with celiac disease are lacking in vitamin D. Poor dietary intake levels and a lack of sunshine are both likely reasons for this. But, those with celiac disease are at a greater risk of being deficient because of the effects of gluten intolerance on the gut’s absorptive properties.

For people with celiac who’ve yet to start a gluten-free diet, or for those who don’t stick with it, atrophy of intestinal villi (fingerlike projections in the gut’s lining) causes malabsorption of nutrients. These villi are intended to increase the surface area of the digestive tract, and when they start to get worse due to exposure to gluten, you are not absorbing vitamins from the food you’re consuming.

People with celiac disease are at an increased risk of osteoporosis as their reduced power to absorb vitamin D hurts their ability to form the hormone calcitriol. This in turn leads to insufficient dietary calcium absorption. To balance for the lack of calcium coming into the system from food, the body must take calcium from skeletal stores, thereby weakening existing bone and preventing new strong bone formation.

How Is Depression Linked?

Depression is one of the major signs of a vitamin D deficiency. Vitamin D comes in two different forms. They are known as D2 and D3. D3 is the type you get through the sun’s rays, as well as the form linked with depression relief.

Studies have found that those with the lowest levels of vitamin D were up to 11 times more likely to be depressed than those with normal vitamin D stores. This is potentially caused by the effect of vitamin D on brain proteins that influence mood, learning, social behavior, maternal instinct, motor control and memory. This has grave social implications when we consider the global prevalence of this deficiency.

Vitamin D Foods

What Foods Should I Eat?

In response to the prevalence of rickets at the turn of the century, the U.S. and Canada began fortifying foods, in particular cow’s milk, with vitamin D in the 1930s. Vitamin D is found in fortified foods and supplements in two forms: D2 (ergocalciferol) and D3 (cholecalciferol).

Your body is able to make D3 when exposed to sunlight. This is also the type of vitamin D found in oily fish and eggs. D3 is the type preferred by receptors in your body. That means that the sun and animal products are the better sources of this vitamin.

Vitamin D2 is the type that’s produced by some mushrooms and other fungi when exposed to ultraviolet radiation. This is often the form used to fortify milk, orange juice, cereals, margarine and other foods.

Today, fortified milk and breakfast cereals are the leading sources of dietary vitamin D in the U.S. Almost all milk produced in the States is fortified with 400 IU of vitamin D per quart. Sadly, current studies show that fortification hasn’t proven effective in preventing hypovitaminosis D. This is particularly the case for those living at high latitudes.

Why hasn’t fortification boosted levels? This is due in large part to the fact that milk isn’t uniformly consumed in the U.S. Also, dairy is often one of the first things people take out of their diets when they get serious about a dieting regime. This finding highlights the importance of seeking natural sources of vitamin D, however, scarce they may be. Try to include those foods in your daily diet.

Fish Is One Of The Best

Don’t like fish? Change. Fatty fish such as tuna, salmon, swordfish and mackerel are some of the only vitamin D rich food sources that aren’t fortified. Cod liver oil is another great source of It. With only one tablespoon of it, you get 340% of your daily value. Small amounts of this vitamin are also found in beef liver, cheese, yogurt and egg yolks.

Fatty fish has more vitamin D than fortified foods such as milks. As little as 3 ounces of sockeye salmon has 112% of your advised daily value intake. Compare that to one cup of fortified milk. That cup only has 29% of your daily value.

You should choose wild salmon instead of farm salmon. Why? Farm salmon only has about 25% of the vitamin D found in wild salmon. Caviar and fish roe are also great sources of vitamin D, as well as vitamin A, vitamin B and potassium. Because of the vitamin D density of fatty fish, many experts advise eating three to four servings a week.

Are There Other Foods Rich In
This Vitamin?

Don’t fall for all the hype. Many foods that aren’t commonly accepted as health foods are also great sources of vitamin D. According to the Weston A. Price Foundation, pork lard is one of the better fats, with this vitamin  levels reaching 1000 IU per tablespoon.This Vitamin from lard helps the body absorb calcium, removes toxins and maintains healthy hormonal function.

Because of their high cholesterol status, egg yolks are also often dismissed by the health conscious. In fact, eggs coming from pastured chickens have four to six times the vitamin D than usual eggs, with the bulk of the vitamin being found in the yolk.

The main reason to get your vitamin D through natural sources is because doing so will ensure you don’t get too much. It’s almost impossible to get too much of any one nutrient from a whole foods diet. On the other hand, a diet rich in fortified foods and vitamin supplements can be a precursor for hypervitaminosis and toxicity.

In a study in the American Journal of Public Health, 41 of 56 people who ate too much vitamin D from over-fortified milk were hospitalized and two people died. While rare, its implications are serious. You’ll likely never have to worry about it. But, stick to natural sources to be on the safe side.

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Vitamin D is one of the more elusive vitamins. Far too many people do not get enough. Why? Most don’t get enough sun. And, it’s hard to get enough of it in your diet.

But, more time in the sun, eating vitamin D-rich foods and supplements are all great ways to avoid It deficiency. Lifestyle changes such as spending more time outside, increasing intense activity, and keeping an eye on your nutrient intake will all help you keep your vitamin D levels in check.

By Lillian Dumont

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Gym Junkies Founder & Editor in Chief at Gym Junkies LLC
I’m Terry and I’m here to help you achieve your fitness goals. I truly believe anyone can achieve the figure they want with the proper guidance. Through my extensive fitness blog, top fitness videos, leading workout supplements, and top selling eBooks, I have been able to help thousands of people online lose weight, tone up and get in shape. My passion is helping people all around the world change their lives for the better.
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