Vitamin D

recommendation by pharmacist

Also known as calciferol, ergocalciferol or D₃, evidence clearly indicates that the general population is not getting enough of it. In fact, our indoor lifestyle (for example, surfing the internet and playing on the XBox) means that we no longer get sufficient amount for our body's needs from sun light exposure.

Very simple. Take 1,000 IU daily along with sufficient calcium intake. That's it. Remember, you are not doing this for just your bones. It's for the health of your entire body.

Deficiencies (or insufficiencies) in important vitamins such as vitamin D (Vit D) may be responsible for many of diseases that are seen in society today. The best and most reliable source of vitamin D is through taking a supplement. Buy it and take it. Vitamin D supplements are incredibly cheap.

Most people are not getting sufficient vitamin D. In our pharmacy practice, we are recommending practically all healthy adults to take 1,000 IU daily of vitamin D along with sufficient calcium of 1,200 mg (from dietary sources and/or supplements).

Table of Contents

Facts about Vitamin D
Suggested Benefits and Traditional Uses
Signs and Symptoms of Deficiency
Possible Causes of Vit D Deficiency
Side Effects, Toxicity and Warnings
Foods that contain this vitamin
What about getting it from sunlight?
Dosage & How to Take It

Evidence of Benefits (Leaf Rating System)

	Osteoporosis The daily intake of Vit D is required to prevent osteoporosis (along with calcium). Vit D is required for the body to absorb calcium. Taking calcium with Vit D will help prevent bone loss and to heal broken bones.
	Osteomalacia (softening of the bones) This vitamin D is effective when taken to prevent osteomalacia caused by liver disease, digestive and absorption problems or certain drug use (such as corticosteroids).
	Preventing Falls in Adults There is evidence that taking Vit D reduce falls in adults by 22%. Calcium by itself does not show this benefit; it is the combination of this vitamin with calcium that helps. Experts do not think it is because of the increase in bone strength and mass that are responsible for this.
	Cancer Prevention Dosage of 1,000 IU daily is safe to use and is currently recommended by experts for male and female adults. Laboratory research shows that this vitamin has anti-cancer benefits. For example, it has been shown to stop the growth of prostate cancer cells in a lab setting and in population studies. Also, research studies show that 800 IU/day of Vit D and 1800 mg/day of calcium seems to prevent and treat colorectal cancer. Clinical research shows that it significantly lowers cancer risk in healthy postmenopausal women. Also epidemiological (population) studies clearly show that men with high levels have a reduced risk of cancer as listed: 17% reduction in all types of cancer 43% reduction in stomach and intestine cancer 25% reduction in deaths due to cancer Well-designed clinical research studies will be required to find out the exact benefits in reducing cancer risks.
	Asthma / Bronchitis / Chronic Obstructive Pulmonary Disease (COPD) Population studies seem to suggest that people with higher levels of Vit D in the blood have a lower risk of having lower lung function. Researchers suspect that Vit D is involved in repairing lung tissues and decreasing inflammation in the lungs.
	Allergies / Hay Fever Low levels of Vit D is associated with an increased chance of developing allergies. This vitamin plays an important role in regulating the immune system. And allergies is a condition where the immune sytem is overreactive to otherwise harmless substances.
	Prevention of Flu (Influenza) in Children A study showed that Japanese shool-aged children taking this 1,200 IU daily of vit D during the winter flu season reduce the number of cases of influenza type A (and not type B) infections.
	Low Sperm Motility In both animal and human subjects, low blood levels of this vitamin seem to impair sperm motility as well to as cause higher numbers of abnormally shaped sperm cells. See increasing sperm motility and boosting fertility with this vitamin for the research studies.
	Depression A study showed that older men and women with lower levels of vitamin D seem to be more likely to develop depression as they aged. (See this news release).
	Type 2 Diabetes One study showed that by using a dose of 2,000 IU daily of this vitamin for 4 months, diabetic patients improved the function of their pancreas by 24%. See Vitamin D for Diabetes for the results from this study. Population studies show that people with lower levels of Vit D seems to be more likely to develop type 2 diabetes (non-insulin dependent diabetes). Also infants taking this vitamin during their first year of life seem to have reduced risk of getting type 1 diabetes later on in life.
	Breast Cancer There are disagreements in research studies on the benefit of Vit D in preventing breast cancer. Some show benefits and other show no effects. In lab studies, Vit D is shown to slow down the growth of cancerous breast tissues. There is no well-designed studies to show if Vit D can prevent breast cancer although experts have reasons to believe that it may be helpful.
	Rheumatoid Arthritis (RA) Population studies point to reduced risk of having RA when intake of Vit D is greater. However, there are no clinical studies to suggest that taking Vit D would help prevent or treat those people suffering from RA. See Vitamin D for Rheumatoid Arthritis for the ressults from studies. See Natural Remedies for Rheumatoid Arthritis for supplements to treat this condition.
	Seasonal Affective Disorder (SAD) SAD is a type of depression that people experience during the dark winter months. The typical treatment involves exposing the individual to bright light from an artificial source. There is some evidence that people with SAD can benefit from taking Vit D supplements.
	Multiple Sclerosis (MS) Population studies seems to show MS is more common in areas where there is less sunlight and that the people eat less fish (a good source of Vit D). Higher levels of Vit D reduce the risk of MS by 40%. However, there are no studies to suggest that taking Vit D would help prevent or treat those people suffering from MS.
	Arthritis Studies seem to suggest that Vit D prevents damage of the cartilage. Low level of Vit D is linked to a higher risk of getting arthritis. However, there are no studies to suggest that taking Vit D would help those with arthritis.
	Premenstrual Syndrome (PMS) Research studies suggest a link between taking more Vit D from diet and the reduced risk of getting PMS.
	High Blood Pressure (Hypertension) Population studies suggest that low levels of Vit D is linked to a higher risk of hypertension. However, there are no studies to suggest that taking Vit D would lower blood pressure.
	High Cholesterol (Hypercholesterolemia / Hypertriglyceridemia) Population studies suggest that lower levels of Vit D is linked to a higher risk of having high cholesterol. However, there are no studies to suggest that taking Vit D would lower high cholesterol.
	Atherosclerosis (hardening of the arteries) Research evidence seems to suggest that no getting enough Vit D might increase the risk of calcium deposits in the arteries (which leads to heart attack or stroke). However, there are no studies to suggest that taking Vit D would prevent atherosclerosis.
	Weight Loss / Obesity Prevention Population studies suggest the fact that lower levels of Vit D intake is associated with higher risk of obesity. Other studies suggest that women taking calcium plus Vit D are more likely to lose weight or to keep the same weight. Other studies suggest that your body weight and percentage of body fat decreases with increased level of 25-hydroxy Vit D (calcidiol) levels.
	Psoriasis Research discovered that people with psoriasis seems to have lower levels of Vit D. However, there are no studies to suggest that taking Vit D would help with psoriasis. A prescription synthetic Vit D3 cream (Dovonex / calcipotriene) is used to treat plaque psoriasis.
	Caesarean Section (C-Section) Risk Reduction In one study involving 253 women, 28 percent of the women has C-section with low serum levels compared to only 14 percent with higher serum levels. "In our analysis, pregnant women who were Vit D deficient at the time of delivery had almost four times the odds of caesarean birth than women who were not deficient," said senior lead author Michael Holick, MD, PhD.
	Overall Reduction in Dying An analysis of previously completed research studies (meta-analysis) turned up an interesting discovery. Vit D seems to significantly reduce death by 7% in healthy middle-ages adults who are at a higher risk of bone fractures. They adults were taking between 300 and 2,000 IU daily of Vit D. A recent study involving 13,000 men and women followed for eight and a half year showed that inadequate Vit D increased their risk of death by 26%.
Helpful	Hearing Loss The small bones in the inner ear needs to be healthy to properly conduct sound waves. Since many adults have been shown to be low in this vitamin, the bone may have weaken, causing hearing loss. This vitamin would be helpful in treating this type of hearing loss.

Facts about Vitamin D

What is vitamin D?

It is fat-soluble vitamin. There are several forms of vitamin D, but the most common forms are vitamin D₂ (ergocalciferol) and vitamin D₃ (cholecalciferol). The term "vitamin D" refers to both these forms.

The body cannot produce Vit D₂, thus we must get it from our diet (from fungal or plant sources). The body can produce Vit D₃ on the skin upon exposure to ultraviolet (UV) B rays from the sun.

Studies suggest that D₃ is more potent than D₂ in our body.

Both D₂ and D₃ are considered to be prohormone as they are not active until they are activated by our body.

The chemistry of vitamin metabolism is complex. D₂ and D₃ are converted by the liver to calcidiol (25-hydroxy Vit D) and stored until needed. This is the form that testing lab will check for (the best measure of Vit D levels in our system).

Then calcidiol is converted by the kidney to calcitriol, the biologically active form of Vit D.

chemical formula structure vitamin d calcitriol

1,25-dihydroxycholecalciferol (1,25(OH)2D₃ or calcitriol)
Chemical formula of calcitriol

What does Vitamin D do in our body?

Vit D receptors exist on most cells of our body and thus serves to modulate or regulate various functions such as:

Promote calcium absorption in the intestine
Promote absorption of calcium into the bone
Regulates calcium and phosphorus levels in the blood
Prevention of osteoporosis (along with adequate calcium intake)
Modulate muscle function
Modulate the immune system
Regulate cell growth and differentiation

What are the levels of Vitamin D?

There is debate over what is a suitable level for Vit D in our body. Below is a table listing what the expert currently agree on.

ng/mL	nmol/L	Comments
<11	<27.5	Deficient
<15	<37.5	Insufficient for health in adults
>30	>75	Suggested for maintaining health in adults (but more evidence will be required from additional research studies)
>200	>500	Considered excessive and may be toxic. Animal studies show that 400 ng/mL (1000 nmol/L) was safe.

Most lab blood test considers 19 to 95 mg/mL (50 to 250 nmol/L) as a normal range for serum levels in a healthy adult. However, that might possibly change with future research studies.

Blood test for vitamin D is no usually done by your family physician and most modern medical labs do not routinely test for vitamin D deficiency.

Suggested Benefits and Traditional Uses

Orally

allergies
asthma
atherosclerosis (hardening of the arteries)
breast cancer
bronchitis
cancer (general risk reduction)
caesarean section (C-section) prevention
colorectal cancer
chronic obstructive pulmonary disease (COPD)
depression
diabetes (type 1 and type 2)
enhance immune functions
fibromyalgia
heart disease prevention
hearing loss
high blood pressure (hypertension)
high cholesterol
hypoparathyroidism (lower parathyroid gland activity)
insulin resistance
migraine
multiple sclerosis (MS)
muscle weakness and spasm
Obesity prevention
osteoarthritis
osteomalacia (softening of the bone)
premenstrual syndrome (PMS)
preventing bone fractures
preventing falls
prevention of osteoporosis
prevention of rickets
prostate cancer
psoriasis
rickets (and Vit D resistant rickets)
rheumatoid arthritis
scleroderma (hardening of the skin and certain organs)
seasonal affective disorder (SAD)
skin cancer
tuberculosis
weight loss / obesity

Topically (on the skin)

psoriasis

Signs and Symptoms of Deficiency

Rickets - Softening and weakening of the bones in children. This is a very rare condition today as milk products are fortified with Vit D. It is still a common childhood disease in many developing countries.

Osteomalacia - Softening and weakening of the bones in adults. (This condition is termed rickets if it happens in children.)

Potential Risk If You Are Deficient - Not getting Vit D may increase your risk of developing the following conditions. However, if you suffer from one or more of the health ailments listed below, it does not necessarily mean that you are low in Vit D.

Osteoporosis
Osteomalacia
Arthritis
Depression
Mood swings
Muscle and bone pain and weakness
Heart disease
Stroke
Cancer
Diabetes
Poor immune function
Weight gain
Insomnia / sleeping problems

What can cause vitamin D deficiency?

Here is a list of possible causes:

Insufficient dietary intake of Vit D rich foods
Kidney disease
Liver disease
Limited or no exposure to sunlight
Use of certain prescription and non-prescription medications
Obesity
Duodenal Switch (DS) surgery
LAP BAND surgery
Other gastric bypass (GBP) surgery

Side Effects, Toxicity and Warnings

Vitamin D is safe to use at all ages in appropriate doses.

There are very few side effects of Vit D when taken in appropriate doses.

Overdose Symptoms

Excess Vit D occurs when you take too much supplement but this is rare. It is very unlikely that you to ever get too much Vit D from sunlight exposure or from food sources.

Listed below are some toxicity symptoms from taking too much of Vit D:

Vomiting
Diarrhea
Constipation
Muscle pain and problems
Poor appetite / no appetite
Weight loss
Skin rash or itch
Fatigue / tiredness / sleepiness
Excessive thirst
Excessive urination
Bone pain
Headache
Anemia
Hypercalcemia (too much calcium in the blood)
Seizures
Decreased growth in children
Pancreatitis (inflammation of the pancreas)

Severe toxicity may occur in doses of 50,000 IU daily if taken for several months.

The use of ultra-high dose is reserved for very specialized or uncommon medical conditions only and blood levels must be done regularly to avoid toxicity. Direct medical supervision is required when taking this vitamin at this or other high dosages.

Safety - This vitamin is very safe when used in appropriate amounts along with sufficient calcium and magnesium intake (either from supplements or from dietary sources). It is as safe to use during pregnancy and when a woman is breastfeeding her baby.

Foods that contain Vitamin D

Naturally rich sources of Vit D are not common. The following food sources contain high amounts of Vit D.

Cold liver oil	1 tablespoon / 15 mL	1360 IU
Salmon	3 & 1/2 ounce	360 IU
Makerel	3 & 1/2 ounce	345 IU
Canned tuna	3 ounce	200 IU
Milk (fortified)	1 cup	10 IU
Egg	1 egg yolk	20 IU

Note: 40 IU Vit D equals 1 mcg (microgram).

Vegetables is not a good source of Vit D. Mushroom contains about 26 IU per half a cup.

Practically all multivitamins contain some amount of Vit D.

What about getting vitamin D from sunlight?

Sunlight exposure of the skin generates sufficient Vit D for most people. 45 minutes of sunlight exposure to the face and arms weekly is usually enough for a fair-skinned person. A person with a darker skin might need 2-3 hours.

The body stores Vit D in the fat tissue for use when there is no sun exposure.

The amount of sunlight exposure various significantly depending on weather (e.g. clouds and smog), clothing worn and the use of sunscreen.

Also, cloudy skies block UV energy by up to 50% and UVB rays do not penetrate through glass.

There is strong evidence that people are suffering from insufficient Vit D, even in Canada and northern parts of US. As well, the elderly are at a higher risk of suffering from lower Vit D levels.

The use of sunscreen significantly reduces Vit D production by sunlight.

Moreover, exposure to sunlight increases your risk of developing skin cancer and prematurely ages your skin. There is no agreement on what is the appropriate balance between the length sun exposure needed for producing Vit D and the risk a person would face from too much exposure.

Although sun exposure is the best source for vitamin D, the risk of excessive sun exposure must be considered. Also, the amount and intensity of the sunlight is so different from place to place, day to day and month to month. It is difficult to know if you are getting enough.

Dosage & How to Take It

The dosages listed below are the suggested requirements by our body as established by experts. Vit D is available as a tablets, liquid drops and injections.

Dosage up to 2,000 IU daily is safe for people over 18 years of age.

The upper limits (UL) is 2,000 IU daily.

Infants to children up to 18 years old require 200 IU daily.
Adults up to 50 years old require 400 IU daily.
Pregnancy women require 400 IU daily.
People over 50 years old / elderly - 600 IU daily.

Also take sufficient amounts of calcium and magnesium (1,200 to 1,400 mg of calcium daily). High levels of Vit D in the absence of enough calcium intake will cause calcium to come out of the bone (a process called demineralization).

Related Articles and Resources

Vitamin D Overdose - How Much is Too Much?

Does Taking Vit D prevent flu?

Does Taking Vit D help with depression?

Return to Natural Remedies List

References
Revised: April 20, 2013