Fiber Fiber

Vitamin D is important for good overall health and strong and healthy bones. It’s also an important factor in making sure your muscles, heart, lungs and brain work well and that your body can fight infection.
Your body can make its own vitamin D from sunlight. You can also get vitamin D from supplements and a very small amount comes from a few foods you eat.
The vitamin D that you get in your skin from sunlight, and the vitamin D from supplements, has to be changed by your body a number of times before it can be used. Once it’s ready, your body uses it to manage the amount of calcium in your blood, bones and gut and to help cells all over your body to communicate properly.

What does vitamin D do?

Vitamins are chemicals that are needed by your body for good health. They are vital for everyone and ensure that your body works well, is able to fight illness and heal well.
The link between vitamin D and strong healthy bones was made many years ago when doctors realized that sunlight, which allows you to produce vitamin D, or taking cod liver oil, which contains vitamin D, helped to prevent a bone condition called rickets in children. Today, vitamin D is seen as a vital part of good health and it’s important not just for the health of your bones. Recent research is now showing that vitamin D may be important in preventing and treating a number of serious long term health problems.
Vitamin D isn’t like most other vitamins. Your body can make its own vitamin D when you expose your skin to sunlight. But your body can’t make other vitamins. You need to get other vitamins from the foods you eat. For example, you need to get vitamin C from fruits and vegetables.
Also what makes vitamin D unique compared to other vitamins, is that when  your body gets its vitamin D, it turns vitamin D into a hormone. This hormone is sometimes called “activated vitamin D” or “calcitriol.”
Getting the right amount of vitamin D doesn’t depend on the foods you eat. To get enough vitamin D you need to expose your skin to sunlight regularly and you may also need to take supplements. This makes getting the right amount a little more complex compared to other vitamins and minerals.
Vitamin D is very important for strong bones. Calcium and phosphorus are essential for developing the structure and strength of your bones, and you need vitamin D to absorb these minerals. Even if you eat foods that contain a lot of calcium and phosphorus, without enough vitamin D, you can’t absorb them into your body. Vitamin D is important for general good health, and researchers now are discovering that vitamin D may be important for many other reasons outside of good bone health. Some of the functions of the body that vitamin D helps with include:

• Immune system, which helps you to fight infection
• Muscle function
• Cardiovascular function, for a healthy heart and circulation
• Respiratory system –for healthy lungs and airways
• Brain development
• Anti-cancer effects

Doctors are still working to fully understand how vitamin D works within your body and how it affects your overall health.
If your body doesn’t get enough vitamin D to keep it healthy, this is called vitamin D deficiency. Severe vitamin D deficiency can sometimes cause a condition called rickets in children and a condition called osteomalacia in adults. Both of these conditions cause soft, thin, and brittle bones.
A lack of vitamin D has also been linked to some other conditions such as cancer, asthma, type-II diabetes, high blood pressure, depression, Alzheimer’s and autoimmune diseases like multiple sclerosis, Crohn’s and type-I diabetes.
Your body gets vitamin D mainly from sunlight, though very small amounts can also be found in a few foods. You can also get vitamin D by taking supplements.

How does Vitamin D work?

Vitamin D mainly comes from your skin when it is exposed to sunlight. After that, your body goes through a number of chemical processes to change it so that your body can use it.
When your skin is exposed to the sun, it produces vitamin D and sends it to your liver. If you take supplements or eat foods that contain vitamin D, your gut also sends the vitamin D to your liver. From here, your liver changes it to a substance called 25(OH)D. When your doctor talks about your vitamin D levels, he means the amount of 25(OH)D you have in your blood.
This chemical is sent all over your body where different tissues, including your kidney, turn it into activated vitamin D. This activated vitamin D is now ready to perform its duties. From here, it gets a little complicated, but you can think of activated vitamin D working in two ways:

1. Manages calcium in your blood, bones and gut
2. Helps cells all over your body to communicate properly

As you can see, vitamin D goes a long way from its original form from the skin, supplement or food. But without vitamin D, your body can’t perform at its best.

Vitamin D is a steroid vitamin, a group of fat-soluble prohormones, which encourages the absorption and metabolism of calcium and phosphorous. People who are exposed to normal quantities of sunlight do not need vitamin D supplements because sunlight promotes sufficient vitamin D synthesis in the skin.

Five forms of vitamin D have been discovered, vitamin D₁, D₂, D₃, D₄, D₅. The two forms that seem to matter to humans the most are vitamins D₂ (ergocalciferol) and D₃ (cholecalciferol).

Researchers at the University of Minnesota found that Vitamin D levels in the body at the start of a low-calorie diet predict weight loss success, suggesting a possible role for vitamin D in weight loss.

High blood levels of vitamin D were found to protect even healthy people at a genetic level. Researchers from Boston University School of Medicine found that higher vitamin D levels in healthy individuals have a significant impact on the genes that are involved in several biologic pathways associated with illnesses, including cancer, autoimmune disease, cardiovascular disease and infectious diseases.

Data collected from the National Health and Nutrition Examination Survey (NHANES), USA found that 9% (7.6 million) of children across the USA were vitamin D deficient (defined as less than 15 ng/mL of blood), while another 61 percent, or 50.8 million, were vitamin D insufficient (15 to 29 ng/mL) (reference "We expected the prevalence of vitamin D deficiency would be high, but the magnitude of the problem nationwide was shocking," says lead author Juhi Kumar, M.D., M.P.H., a fellow in pediatrics at Children's Hospital at Montefiore Medical Center, The University Hospital and Academic Medical Center for Albert Einstein College of Medicine.


Vitamin D for humans is obtained from sun exposure, food and supplements. It is biologically inert and has to undergo two hydroxylation reactions to become active in the body. The active form of vitamin D in the body is called Calcitriol (1,25-Dihydroxycholecalciferol).

Calcitriol promotes the absorption of calcium and phosphorus from food in the gut and reabsorption of calcium in the kidneys - this increases the flow of calcium in the bloodstream. This is essential for the normal mineralization of bone and preventing hypocalcemic tetany. Hypocalcemic tetany is a low calcium condition in which the patient has overactive neurological reflexes, spasms of the hands and feet, cramps and spasms of the voice box (larynx). Calcitriol also plays a key role in the maintenance of many organ systems.

Various forms of vitamin D

We know about 5 forms of vitamin D, of which vitamins D₂ and D₃ are the major forms as far as humans are concerned. They are known collectively as calciferol.

• Vitamin D₁, molecular compound of ergocalciferol with lumisterol.


• Vitamin D₂, ergocalciferol (made from ergosterol).
  
  It is produced by invertebrates (animals without a spine, vertebral column), fungus and plants in response to sunlight (UV irradiation). Humans and other vertebrates do not produce vitamin D₂. We don't know much about what vitamin D₂ does in invertebrates. We know that ergosterol is a good absorber of ultraviolet radiation which can damage DNA, RNA and protein; consequently many scientists believe it may serve as a sunscreen that protects organisms from sunlight damage.


• Vitamin D₃, cholecalciferol (made from 7-dehydrocholesterol).
  
  Vitamin D₃ is made in the skin when 7-dehydrocholesterol reacts with ultraviolet light at 270-300 nm wavelengths - peak vitamin D₃ production occurs between 295-297 nm. It is only when the UV index is greater than 3 that these UVB wavelengths are present.
  
  A UV index of more than 3 occurs every day in the tropics, every day during some of spring, all of summer, and parts of autumn in temperate areas, and hardly ever at all in the arctic circles. Temperate regions are all regions outside the tropics and arctic circles. The number of days of the year when the UV index is greater than 3 become fewer the further you move away from the tropics.
  
  A human requires ten to fifteen minutes of sun exposure at least twice a week on the face, arms, hands, or back without sunscreen with a greater than 3 UV index for adequate amounts of vitamin D₃. Longer exposure results in the extra vitamin supply being degraded as fast as it is generated.


• Vitamin D₄, 22-dihydroergocalciferol.


• Vitamin D₅, sitocalciferol (made from 7-dehydrositosterol).

Which is more important for humans, vitamins D₂ or D₃?

Both vitamins D₂ and D₃ are used in human nutritional supplements. Pharmaceutical forms include calcitriol (1alpha, 25-dihydroxycholecalciferol), doxercalciferol and calcipotriene. The majority of scientists state that D₂ and D₃ are equally effective in our bloodstream. However, some say that D₃ is more effective. Animal experiments, specifically on rats, indicate that D₂ is more effective than D₃.

What do we need vitamin D for?

• It is crucial for the absorption and metabolism of calcium and phosphorous, which have various functions, especially the maintenance of healthy bones.


• It is an immune system regulator.


• It may be an important way to arm the immune system against disorders like the common cold, say scientists from the University of Colorado Denver School of Medicine, Massachusetts General Hospital and Children's Hospital Boston.


• It may reduce the risk of developing multiple sclerosis. Multiple sclerosis is much less common the nearer you get to the tropics, where there is much more sunlight, according to Dennis Bourdette, chairman of the Department of Neurology and director of the Multiple Sclerosis and Neuroimmunology Center at Oregon Health and Science University, USA.


• Vitamin D may have a key role in helping the brain to keep working well in later life, according to a study of 3000 European men between the ages of 40 and 79.


• Vitamin D is probably linked to maintaining a healthy body weight, according to research carried out at the Medical College of Georgia, USA.


• It can reduce the severity and frequency of asthma symptoms, and also the likelihood of hospitalizations due to asthma, researchers from Harvard Medical School found after monitoring 616 children in Costa Rica.


• It has been shown to reduce the risk of developing rheumatoid arthritis in women.


• A form of vitamin D could be one of our body's main protections against damage from low levels of radiation, say radiological experts from the New York City Department of Health and Mental Hygiene.


• Various studies have shown that people with adequate levels of vitamin D have a significantly lower risk of developing cancer, compared to people with lower levels. Vitamin D deficiency was found to be prevalent in cancer patients regardless of nutritional status, in a study carried out by Cancer Treatment Centers of America.


• High vitamin D doses can help people recover from tuberculosis more rapidly, researchers reported in September 2012 in the Proceeding of the National Academy of Sciences (PNAS).


• An additional study published in September 2012 suggested that low levels of vitamin D may increase the risk of heart attack and early death.

A study published in JAMA in October 2012 found that vitamin D does not help reduce how often or how severely we catch colds.

Sunlight and vitamin D requirements

If you live in the tropics and can expose your unprotected skin to two sessions of 15 minutes of sunlight each week your body will naturally produce adequate amounts of vitamin D. The following factors may reduce your body's vitamin D synthesis:

• If you live far from the equator, your sunlight exposure will be less during many months of the year.
• Cloud cover
• Smog
• Sunscreens

If your body cannot produce enough vitamin D because of insufficient sunlight exposure you will need to obtain it from foods and perhaps supplements. Experts say that people with a high risk of vitamin D deficiency should consume 25 μg (1000 IU) of vitamin D each day so that there is a good level of 25-hydroxyvitamin D in the bloodstream. Elderly people, as well as people with dark skin should consume extra vitamin D for good health.

Vitamin D levels in women in winter - women with arthritis, diabetes and some other chronic conditions are much more susceptible to drops in vitamin D levels during the winter months, researchers from Vanderbilt University Medical Center in Nashville, Tenn., reported at the 2012 American Society of Clinical Pathology Annual Meeting. They added that doctors should become aware of this and help these patients maintain adequate levels of vitamin D during the winter season.

How much vitamin D do I need?

The information below relates to people who do not have exposure to sunlight.

United States

According to the Institute of Medicine of The National Academies, which created the Dietary Reference Intakes (DRIs), people should be intaking the following amounts of vitamin D if nothing is being synthesized (no sunlight exposure):

• 1-70 years of age: 600 IU/day (15 μg/day)
• 71+ years of age: 800 IU/day (20 μg/day)
• Pregnant/lactating: 600 IU/day (15 μg/day)

The American Academy of Pediatrics recommends that exclusively or partially breastfed babies should receive supplements of 400 UI per day shortly after birth, and when they are weaned they should consume a minimum of 1,000 mL/day of vitamin D fortified formula or whole milk. Non-breastfed infants consuming less than 1,000 mL/day of vitamin D-fortified formula or milk should receive a vitamin D supplement of 400 IU per day. It also recommends that older children and adolescents who do not get 400 IU per day through vitamin D fortified milk and foods should take a 400 IU vitamin supplement each day.

Canada

The following are the recommended dietary allowances (RDA) for vitamin D from Health Canada:

• Infants 0-6 months 400 IU*
• Infants 7-12 months 400 IU*
• Children 1-3 years 600 IU
• Children 4-8 years 600 IU
• Children/Adults 9-70 years 600 IU
• Adults more than 70 years 800 IU
• Pregnancy & Lactation 600 IU

* Adequate Intake rather than RDA

United Kingdom

The Department of Health recommends that:

• Breastfeeding and pregnant women should take a daily vitamin D supplement containing 10 mcg (400 IU), to make sure her their requirements are met as well as building up adequate fetal stores for early infancy


• Babies and young children from 6 months to 5 years should take a daily vitamin D supplement in the form of drops of 7 to 8.4 mcg (approx 300 IU)


• Babies on infant formula do not need vitamin D supplements until they are consuming less than 500 ml per day (formula is fortified with vitamin D)


• Breastfed babies may need vitamin D drops from the age of one month if the mother did not take supplements while she was pregnant


• Pensioners (seniors, aged 65+) as well as individuals who do not get much direct sunshine on their skin should take 10 mcg (400 IU) per day

Vitamin D doses for infants vary according to country and seasons

In an article published in JAMA (Journal of the American Medical Association (May 2013 issue), researchers from McGill University, Canada wrote that infants should received a daily dose of vitamin D of 400 IU.

The daily recommended dose for infants in France and Finland is 1,000 IU, while Health Canada and the World Health Organization recommend 400 IU.

The Canadian Pediatric Society recommends that in Canada infants should receive 800 IU per day in the winter when there is less sunlight.

Vitamin D and nutrition

Over the last few hundred years human lifestyles have changed. The industrial revolution resulted in more indoor work and less exposure to sunlight. Many societies around the world wore more clothing over the centuries, further reducing skin exposure to sunlight. These changes have brought with them a significant reduction in the natural production of vitamin D and subsequent diseases.

Countries responded to these changes by fortifying some foods with vitamins D₂ and D₃, examples include breakfast cereals, bread, pastries, oil spreads, margarine, milk and other dairy products. Initially, some scientists complained that nutritional fortification and recommended supplementation doses were not making up for the shortfall. These people were ignored, and sometimes ridiculed - however, over the last few years studies indicate that they may have been right after all.

Not that many foods contain vitamin D. Some fish, such as salmon, tuna and mackerel, as well as fish liver oils are considered to be the best sources. Some vitamin D is also present in beef liver, cheese and egg yolks. Most of these are Vitamin D₃. Some mushrooms provide variable amounts of vitamin D₂.

Most of the food sourced vitamin D in the western diet comes from fortified foods - where vitamin D is artificially added. Most US milk is fortified with 100 IU/cup of vitamin D. In the 1930s milk was fortified in many countries to combat rickets, which was a major health problem then.

Vitamin D levels in pregnancy protects mother but not baby from MS

Pregnant women, and women in general, have a lower risk of developing MS (multiple sclerosis) if their vitamin D levels are high. Researchers from Umeå University Hospital added that the developing fetus does not appear to receive the same protection if the mother's vitamin D levels are high. They reported their findings in the journal Neurology.

Study author, neurologist Jonatan Salzer, MD said:

"In our study, pregnant women and women in general had a lower risk for MS with higher levels of the vitamin, as expected. However, a mother's levels of vitamin D during early pregnancy did not have an effect on MS risk for her baby."

-- Ease Stress
-- Treat anxiety and depression
-- Aid memory
-- Relieve PMS
-- Reduce heart-disease risk
--vitamin b complex
The 11 members of what's known as the vitamin B complex are critical nutrients for all things mind-related: mood, memory, even migraines can benefit from the B's. In the right amounts, the B's can quell anxiety, lift depression, ease PMS, and boost your energy. And getting them couldn't be easier.

The B vitamins are a chemically related family of nutrients that work as a team. Their mood-boosting and other health benefits (see chart below) result from intricate behind-the-scenes work in the body.
Some B vitamins help cells burn fats and glucose for energy. Others help make neurotransmitters like serotonin. And some B's assist with the production and repair of DNA.

Many of us don't get enough B's; according to the USDA, deficiencies in folic acid, B12, and B6 are especially common. Ensuring that your diet contains plenty of B-rich foods -- dark-green vegetables, protein from animal sources, and whole grains -- is critical.But if your stress level is high or your mood feels off-kilter, or if your diet is low in B's, you'll benefit from the higher amounts found in supplements.

Breaking down the B'sThe dosage ranges shown in the chart below are commonly used for prevention and treatment of specific conditions. Be sure to consult a physician if you're interested in taking B's for medicinal use.
Thiamine (B1)Requirements increase with diets high in carbs and sugars
10-100 mg
Riboflavin (B2)Higher doses shown to reduce migraine headaches
10-400 mg
Niacinamide (B3)Helps increase energy; needed for DNA repair; niacin form can cause flushing
50-100 mg
Pyridoxine (B6)Needed for neurotransmitters, such as serotonin; may relieve PMS
10-50 mg
Pantothenic acidSpeeds wound healing; high doses of panethine form can reduce cholesterol levels
10-100 mg
Folic acid (B9)Lowers risk of heart disease, stroke, and birth defects; colon-cancer prevention
400-800 mcg
Cyanocobalamin (B12)May improve memory and reverse mental fogginess
20-1,000 mcg
BiotinHigh dosages, combined with chromium, improve blood-sugar control
30-100 mcg
CholineNeeded for normal brain and memory function
50-200 mg
InositolHelpful for depression and anxiety attacks
50-200 mg
Para-amino benzoic acid (PABA)One of the few nutrients beneficial in scleroderma, a connective-tissue disease
30-100 mg
Find the best B complex

To get the most benefits from any of the B's, you need all of them, so start with a B-complex supplement that contains all 11. With the right B complex as a foundation, you can add larger amounts of individual B's depending on your health concerns.

The B's are best taken with food -- they can cause nausea when taken on an empty stomach -- and early in the day. (Vitamin B6 increases neurotransmitter activity; when taken late in the day, it can lead to increased dreaming, resulting in a restless night's sleep.)

Potassium is an essential nutrient used to maintain fluid and electrolyte balance in the body. A deficiency in potassium causes fatigue, irritability, and hypertension (increased blood pressure). Unless you are on dialysis, or have a special condition, overdose of potassium from natural sources is nearly impossible; however, it is possible to consume too much potassium via potassium salts which can lead to nausea, vomiting, and even cardiac arrest. Potassium from natural food sources, like the ones listed below, are considered safe and healthy. The current percent daily value for potassium is a whopping 3.5 grams, below is a list of high potassium foods ranked by common serving sizes. For more foods high in potassium please see the lists of high potassium foods by nutrient density, potassium rich foods, fruits high in potassium, and vegetables high in potassium.

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#1: White Beans

Potassium in 100g	1 cup cooked (179g)
561mg (16% DV)	1004mg (29% DV)

Other Beans High in Potassium (%DV per cup): Adzuki (35%), Soy (28%), Lima (28%), Kidney (20%), Great Northern (20%), Pinto (18%) and others at an average of 15% DV per cup cooked.

#2: Dark Leafy Greens (Spinach)

Potassium 100g (Raw)	1 Cup (Raw - 30g)	1 Cup (Cooked - 180g)
558mg (16% DV)	167mg (5% DV)	839mg (24% DV)

Other Greens High in Potassium (%DV per cup cooked): Swiss Chard (27% DV), Kale (8% DV), and Collards (6% DV). 

#3: Baked Potatoes (With Skin)

Potassium 100g	Average Potato (173g)
535mg (15% DV)	926mg (26% DV)

Warning: Potatoes are high in simple carbohydrates and not recommended for people with diabetes. Sweet potatoes are actually better for regulation blood sugar, an average baked sweet potato with skin (114g) provides 542mg (15% DV) of potassium. 

#4: Dried Apricots

Potassium 100g	1/2 cup (65g)
1162mg (33% DV)	755mg (22% DV)

Other Dried Fruits High in Potassium (%DV per 1/2 cup): Peaches (22% DV), Prunes (20% DV), Raisins (18% DV).
Warning: Dried fruits are high in sugar.

#5: Baked Acorn Squash

Potassium 100g	1 cup cubed (205g)
437mg (12% DV)	899mg (26% DV)

Other Squash High in Potassium (%DV per cup baked): Hubbard (21%), Butternut (17% DV), Zucchini (14% DV), Average Winter Squash (10% DV).

#6: Yogurt (Plain, Skim/Non-Fat)

Potassium 100g	1 cup (245g)
255mg (7% DV)	625mg (18% DV)

Other Yogurt High in Potassium (%DV per cup): Whole-Fat (11% DV), Chocolate Yogurt (24% DV).

#7: Fish (Salmon)

Potassium 100g	1 3oz fillet (85g)
628mg (18% DV)	534mg (15% DV)

Other Fish High in Potassium (%DV per 3oz fillet (85g)): Pompano (15% DV), Lingcod (14% DV), Halibut (13% DV), Yellowfin Tuna (13% DV), Anchovies (12% DV), Mackerel (10% DV), Herring (10% DV) and most other fish at an average of 10% DV.

#8: Avocados

Potassium 100g	Average Avocado (201g)	1/2 Cup Pureed (115)
485mg (14% DV)	975mg (28% DV)	558mg (16% DV)

An average avocado provides 322 calories, half a cup purred contains 184 calories.

#9: Mushrooms (White)

Potassium 100g	1 cup sliced (108g)
396mg (11% DV)	428mg (12% DV)

1 cup cooked sliced white mushrooms contain 28 calories.
Other mushrooms high in potassium (%DV per cup sliced): Portabella (9% DV), Brown or Crimini (9% DV), Enoki (7% DV), Shiitake (5% DV), Maitake (4% DV). 

#10: Bananas

Potassium 100g	Average Banana(118g)	1 Cup Mashed (225)
358mg (10% DV)	422mg (12% DV)	806mg (23% DV)

An average banana provides 105 calories, 1 cup mashed contains 200