Health Benefits of Vitamin D, According to Science - Jenn Miller
Vitamin D, sometimes referred to as the “sunshine vitamin”, is a hormone-like, fat-soluble vitamin that your body produces when it is in direct contact with sunlight. Sunscreen however, important for protection from melanoma and rapid ageing of the skin, blocks these rays. So while we do make it naturally, it is recommended to take supplements.
Vitamin D is vital to the intestinal absorption of many minerals and vitamins that we need to stay healthy and a lack of vitamin D can have dire consequences on our bones, immune system and heart health.
Approximately 10 percent of American adults are vitamin D deficient, however vitamin D deficiencies affect all ages at all stages of life. A vitamin D deficiency is characterised by the following symptoms:
- Weak muscles
- Bone pain
- The inability to think clearly
- A frequency of bone injuries such as breaks and fractures
- Excess sweating
- Soft bones
Every single cell in your body relies on vitamin D in order to function normally.
1. Vitamin D Fights Seasonal Depression
Seasonal Affective disorder (SAD or also known as winter blues) is when your mood and temperament is affected by the weather or the lack of sunlight during the winter months in colder countries (1). Colder and darker weather affects your mood as the production of serotonin (a neurotransmitter produced in the brain that maintains mood balance) is linked to the amount of sunlight you get. Symptoms of SAD include;
- Weight gain
- Feeling depressed
- Feeling lethargic
- Becoming quickly irritated
- Having difficulty concentrating
- A decreased libido
- An increased intake of food
A randomised medical trial has found a relationship between a lack of vitamin D and SAD (2). Brain tissues contain vitamin D receptors and when these receptors are activated they stimulate and increase the growth of nerves within your brain. This process is important to mental health and brain function .
2. Vitamin D Can Ensure A Healthy Pregnancy
An expectant mother with a vitamin D deficiency in her first trimester is at risk of having a baby with extremely low birth weight. A study funded by the University of Pittsburgh found that low levels of vitamin D in the early stages of pregnancy put a baby at risk of stunted growth while in utero (3).
Babies that are born smaller are ultimately born with a higher risk of developing heart disease, diabetes and hypertension later on in life as well as a high risk of mortality within the first month after birth.
Vitamin D is so important for pregnancies because of the vitamin D receptors present in gestational tissues (4). Vitamin D2 and 3 are the most important compounds for human development (5).
10 micrograms per day is recommended for pregnant and breastfeeding mothers (6).
3. Vitamin D Supports Healthy Lung Function
Obstructive pulmonary disease (including emphysema and bronchitis, various diseases that have been grouped as they are all characterised by obstruction in the lungs resulting in poor airflow) and asthma are two chronic lung diseases that are worsened by a lack of vitamin D (7).
These diseases are chronic which means that they are permanent.
Studies show a link between a strengthened reaction by the immune system against infection of the airways caused by manufacturing of antimicrobial peptides and vitamin D, especially when combined with the use of an air purifier.
A flare up of any of these lung diseases are characterised by uncontrollable coughing, chest tightness, excess mucus buildup in the lungs and difficulty breathing. These flare ups could result in hospitalisation, or in extreme cases, even death. Studies show the patients suffering from these conditions could decrease their instances of flare ups by nearly 40 percent by taking vitamin D supplements (8).
Vitamin D deficiencies have a physical effect on the shape of the lungs. A study found that vitamin D deficiencies can change the volume of the lungs and the lung development (9).
4. Vitamin D Aids Calcium Absorption
The most important nutrient needed for the correct absorption of calcium in the body is Vitamin D. Without vitamin D our bodies would struggle to absorb calcium at all. Calcium and vitamin D work hand in hand to stave off or reduce the effects of osteoporosis (10).
Calcium is also important for proper heart, muscle and nerve function as well as blood clotting.
As we age our bodies ability to create vitamin D from sunlight exposure and to properly absorb calcium begin to decrease. When our body does not have enough vitamin D it cannot produce a hormone called calcitriol which regulates calcium levels in the body. The body then takes calcium stored within the skeleton. This weakens the existing bones and prevents new bone formation (11).
A serious vitamin D deficiency is likely to result in the development of rickets in young children and can also be responsible for osteomalacia (when bones soften due to a lack of calcium or vitamin D) in adults. (12)
5. Vitamin D Supports The Brain And Nervous System
Vitamin D plays an important role in regulating the health of the brain and nervous system both during its development and throughout the rest of our lives.
Studies carried out on rodents observing the effect of vitamin D on the brain found that pregnant mice that were vitamin D deficient gave birth to babies with thinner and longer brains which had larger than usual ventricles. This unusual brain shape is caused by excess brain cells not dying off when they should. This process of getting rid of unnecessary brain cells is needed for important cell connections to develop within the brain (13).
Mice born to vitamin D deficient mothers also exhibited behaviours similar to behaviours seen in people with schizophrenia and autism.
Hypovitaminosis D is the decline of vitamin D in the system due to old age. Elderly with a lack of vitamin D in their systems are at a higher risk of developing dementia or having a stroke. As of now, five studies have reported a link between hypovitaminosis D and dementia.
6. Vitamin D Promotes Weight Loss
Vitamin D is a fat-soluble vitamin so it is stored within the fat cells in our bodies.
Vitamin D receptors tell the body whether it should store or burn the fat we consume. When you provide these receptors with more vitamin D it promotes the burning of fats over storing it (a). If receptors in your brain do not get enough vitamin D you tend to feel hungrier which can lead to excess snacking.
Research shows that most people battling obesity have much lower vitamin D levels in their blood (14). When a study put 38 overweight adults on a specialised 11 week eating plan it was found that participants who started the diet with higher levels of vitamin D in their blood were more successful in losing weight than participants with low starting levels of vitamin D.
The vitamin D levels in participants were also a precursor to the successful loss of belly or abdominal fat (abdominal fat most notable visceral abdominal fat is particularly harmful as it surrounds your organs and usually leads to health complications like type 2 diabetes, certain cancers and insulin resistance).
Being unable to lose weight could be a sign of a vitamin d deficiency.
7. Vitamin D Fights Disease
Vitamin D is actually a pro-hormone which means that the body is able to convert it into a hormone. When the body is depleted of vitamin D you are at risk of developing heart disease, muscle weakness and some cancers.
Colorectal (cancer of the colon), breast and prostate cancer and the mortality caused by them have been linked to low levels of vitamin D in the blood. Studies have found that an uptake of vitamin D can help protect the body from these cancers (15).
Vitamin D receptors are also found in the nuclei (the nucleus) of the body's immune cells. Further evidence links a vitamin D deficiency to diseases like systemic lupus erythematosus (a disease where your immune system begins to attacks itself causing a rash on the face, severe fatigue and joint pain) and rheumatoid arthritis (16).
A study that hopes to explore the extent to which vitamin D is useful in protecting the body from cancer, diabetes, depression and hypertension is currently underway. The study will span five years and include 20 thousand participants (17).
8. Vitamin D For Healthy Infants And Toddlers
The development of rickets is the potential danger for babies and toddlers that are vitamin D deficient (18). Babies that are at highest risk of developing rickets are babies who have a darker skin tone, those born premature, who are being or have been breast fed and babies whose mothers have low levels of vitamin D.
Vitamin D is essential for normal body development and growth. When a baby is deficient it does not have the correct biological material to build healthy teeth and bones and will most likely have retarded bone growth. A few signs that your baby or young child has rickets are:
- Weakened muscles
- Projection of the breast bone
- Pain and discomfort in the legs, pelvis and or spine
- Thickened ankles and wrists
- Abnormal leg shaped such as knocked knees or bowed legs
- Slow growth (19)
If rickets is not addressed and treated it could lead to permanent skeletal damage, dental defects, seizures and a curved spine. Sunlight is not an option for increasing levels as prolonged direct contact with the sun holds too many risks for infants.
Babies who are breastfed are at a higher risk of vitamin D deficiency as vitamin D is added to infant formula. The recommended dose is 8 to 10 micrograms of vitamin D daily for breastfed infants under the age of one (20).
9. Vitamin D Can Ease Various Skin Issues
Vitamin D receptors in the cells are directly linked to cell differentiation (when a cell becomes specialised to performing a certain function) and cell proliferation (a process which increases cell numbers). These receptors are also linked to healthy immune function, this is important because a weak immune system cannot fight cell damaging free radicals, and free radicals can cause major damage to skin cells (21).
Nearly 40000 of your cells die within a minute. The system of cell renewal is heavily dependant on vitamin D. This process occurs in cell called keratinocytes and they make up over 90 percents of all cells in the epidermis (the skin). When they receive the right amount of vitamin d these cells are able to differentiate and multiply. Because of this these cells provide a constant flow of younger cells to replenish the epidermis and create a layer of moisture trapping tissue.
The actual rate at which cell multiply and differentiate is prompt by vitamin D. When your body does not get enough, this process slows down and skin can become thin and damaged.
Eczema, excess sweating, wrinkles and acne are all signs of vitamin D deficient cells. Vitamin D also acts as an anti-inflammatory within the skin and that can prevent or lessen the severity of acne (22).
Contact with sunlight is one way to get vitamin D but it can also be damaging to skin cells so it is advisable to limit your direct contact with sunlight to less than 30 minutes a day and to use sunscreen. Foods high in vitamin D and supplements are less harsh on the skin.
10. Vitamin D Prevents Erectile Dysfunction
Erectile dysfunction or impotence is when a man is unable to achieve or maintain an erection for the purpose of intercourse. It can be a physiological problem or a physical one. ED has been found to have negative impacts on the self esteem of men suffering and their relationships as well as making it difficult for couples to conceive (23).
ED is a potential risk factor or precursor in developing high blood pressure, heart disease and diabetes.
A study in America carried out on over 3000 men over the age of 20, all suffering from a vitamin D deficiency, found that 16 percent of them had ED (24). The same study stated that men lacking in vitamin D have a 32 percent higher risk of developing ED.
Men who have been diagnosed with ED are likely to also develop endothelial dysfunction (when the capacity of the inner blood vessel linings to control vascular relaxation and regulate immune function and blood clotting becomes compromised). Low vitamin D levels inhibit nitric oxide synthesis. Nitric oxide secretion is key to smooth muscle relaxation in the corpora cavernosa (the bulk of the erectile tissue) (25).
11. Vitamin D Improves Symptoms Of Tuberculosis
Tuberculosis (TB) is a disease of the respiratory system that can also have an impact on the brain, spine and kidneys. Although symptoms do not always occur they include:
- Phlegm build up in the lungs
- Sudden weight loss
- A cough that has persisted for more than three weeks
- Loss of appetite
- Night sweats
- A fever and or chills
- Coughing up mucus and or blood
- Persistent fatigue
TB can be active or dormant. Approximately 1 in 3 people worldwide have dormant TB while 1 in 10 will develop active TB. Drug or alcohol abuse, and having cancer, diabetes or HIV or AIDS can result in dormant TB becoming active as they weaken the immune system (26).
Vitamin D increases the increases the amount of proteins in your immune system that kill foreign and potentially harmful bacteria. Studies show that TB patients who have been given vitamin D doses had faster rates of recovery and experienced fewer TB symptoms.
A study in Pakistan determined that low vitamin D levels were partly responsible for the progression from dormant to active TB. Low vitamin D levels can be looked at as a sign of possible latent TB or a sign of the patient having been diagnosed with TB once before (27).
To treat TB with vitamin D it is recommended to take no more than 10,000 IU (international units) a day.
12. Vitamin D Influences Gene Expression
Vitamin D is involved in the process of gene expression, which is where certain functions of cells are turned off or turned on.
Gene expression is a process in which genes synthesise products (usually proteins that go on to become hormones, enzymes and receptors that carry out important functions) according to genetic instructions provided by our DNA.
An analysis carried out on 8 vitamin D deficient adults found positive changes to the actions of 291 different genes. These genes were directly involved in 160 pathways that are linked to infectious and autoimmune diseases, cancer, the way cells respond to stress, DNA regulation and heart function (28).
Vitamin D down-regulates and up-regulates proteins manufactured by gene regulation (29).
13. Vitamin D Can Ease Multiple Sclerosis
Multiple sclerosis is an autoimmune disease where your immune system targets and damages the myelin sheath that protects your nerve fibres in your spinal cord and brain (the central nervous system) that causes a problem with the communication between the brain and body. MS could eventually cause permanent damage (30).
The symptoms of MS vary. The more damage done to the nerves, the more severe the signs are (loss of vision, feeling permanently fatigued, heavily impaired coordination and pain). At its severest, people with MS may lose the ability to walk.
MS has found to be more common in areas that are further away from the equator and thus get less sun year round (31). Research shows that babies born with lower levels of vitamin D in their blood are more likely to develop MS later on in life.
Patients suffering from MS report less attacks during Summer months which correlates with more exposure to direct sunlight which results in the body creating more vitamin D (32).Studies hoping to determine the effects of vitamin D on myelin repair and its role in neuro-protection are currently underway (33).
14. Vitamin D Improves Your Eyesight
People with low vitamin D levels are at risk of developing wet macular degeneration. Wet macular degeneration is a chronic disease of the eye and causes a person to develop a blind spot in their field of sight or blurred vision. It is caused by unusual growth of blood vessels within the eyes that secrete excess fluid or blood.
Vitamin D prevents angiogenesis, the process by which blood vessels form. It is also an anti inflammatory which also helps to prevent wet macular degeneration as the disease is worsened by inflammation in the eye (34).
15. Vitamin D Improves Metabolic Syndrome
Elevated blood pressure, excess amounts of body fat in the stomach area, atypical cholesterol levels and high sugar levels are all a part of metabolic syndrome. The dangers of metabolic syndrome are high risk of stroke and heart attacks.
Metabolic syndrome affects up to 25 percent of the adult population worldwide. It is caused by a vitamin D deficiency coupled with a diet high in saturated fats and carbohydrates (35).
Vitamin D spurs on manufacturing of defensins, molecules which maintain and restore the health of gut flora (microorganisms in the digestive tract). Healthy bacteria in your gut reduces the fat in the liver and regulates blood sugar.
Vitamin D also boosts the diversity of bacteria in your gut which reduces risk from harmful pathogens (36).
15 Best Vitamin D Foods
1. Egg Yolks
Egg yolks have a bad reputation for being high in cholesterol, and they are, but with High Density Lipoprotein cholesterol which is also known as the “good” cholesterol. HDL cholesterol is considered good because of it’s relationship with LDL cholesterol (low-density protein which is considered the “bad” cholesterol).
HDL searches for and finds LDL within the blood stream. It then takes the LDL to the liver where it is reprocessed. HDL is also constantly working to keep the endothelium (the inside of blood vessels) in good shape. When these inner walls become damaged a process called atherosclerosis begins and the artery walls start to thicken. This can have life threatening results such as strokes and heart attacks.
Eggs yolks are much higher in vitamins than egg whites.
Egg yolks contain the carotenoids zeaxanthin and lutein which together significantly lower the risk of macular degeneration (an age related incurable eye disease) and cataracts. These eye diseases are the result of damage caused by free radicals. The carotenoids are antioxidants which prevent and reverse the damage the free radicals cause.
Choline is an important macronutrient found in egg yolks that most people do not get enough of. Choline is important because it builds and strengthens cell membranes. Choline is also involved in several bodily functions such as brain, liver and muscle function.
Choline aids the development of DNA methylation and an American study found that women with diets that contained high levels of choline had a nearly 25 percent less chance of developing breast cancer.
Salmon is an incredible source of protein. Protein is important as it aids the process of muscle healing caused by ageing and physical activity.
Salmon is also an excellent source of omega-3 fatty acids. Omega-3 is a healthy fat (natural polyunsaturated fat) that our body cannot make by itself. Omega-3 is a popular supplement (fish oil) and offers a range of health benefits including:
- Regulating menstruation and thus improving fertility in women
- Reducing or healing skin ailments such as acne, psoriasis and eczema
- Combatting dry eye syndrome
- Soothing anxiety symptoms
- Strengthening brain growth and development
- Keeping your heart rate normal
- Regulating blood clotting
- Reducing fatty liver
- Lowers cholesterol
- Reversing insulin resistance
- Countering inflammation
- Fighting autoimmune diseases
The calcium content of cheese is very high. Calcium is needed to keep bone and teeth health from deteriorating. Another benefit for teeth is that cheese has a very low lactose content. In high amounts lactose can cause damage to the teeth.
Cheese is high in vitamin B. Vitamin B is an important one for pregnant or lactating women, children and the elderly as it is a vital component in first the formation and then the strengthening of cartilage and bones.
If weight gain is recommended for health, cheese is a good food to include in your diet.
Astaxanthin is a carotenoid found in shrimp. Astaxanthin is an effective antioxidant that reduces damage done to the skin by exposure to direct sunlight and UVA. UVA is responsible for the development of sunspots, premature ageing and wrinkles in the skin.
A zinc deficiency within the body has been found responsible for accelerated hair loss. Zinc (found in shrimp) creates and maintain new cells, including the very cells responsible for the health of skin and hair. Other symptoms of a zinc deficiency include:
- Sudden weight loss
- Development of white spots in the fingernails
- Onset of depression
- Dulling of taste and smell senses
- Unusual bone growth
Shrimp contains omega-3 fatty acids which has exhibited soothing effects of cramping and pain associated with menstruation.
One serving of oysters contain almost 90 percent of the recommended daily requirement of iron. Iron is vital to the process of generation of red blood cells. The increase of oxygenated blood in the body provides the bodies organs with fuel to keep the functioning at optimal levels.
Getting enough iron is essential to combating anaemia, a condition that can result in chronic fatigue, stomach problems, weakening of muscles and cognitive malfunction.
Oysters contain zinc which is a key component in wound healing and accelerated recovery from injury.
Oysters also contain vitamin E which increases the flexibility and strength of the membranes of various cells.
6. Soy Milk
The isoflavones in soy beans have been shown by studies to be beneficial to menopausal women in that it can balance the amount of oestrogen being lost through the process of menopause. The isoflavones are a kind of phytoestrogens, these are plant based (fruits and vegetables) and mimic oestrogen effects within the body.
Soymilk helps to defend the liver from stress caused by oxidation because of its hepatoprotective properties.
Soymilk has added calcium and unlike a diet high in animal protein, a diet high in soymilk protein reduces the likelihood of losing calcium via urinary excretion. These factors make soymilk a good tool for fighting brittle bones and bone break down.
Pork contains vitamin B1 or thiamine. Thiamine has a few important functions within the body including allowing electrolytes to flow into and out of muscle and nerve cells, metabolising carbohydrates and aiding bodily enzymatic processes.
The body does not produce thiamine and can only retain it for about 18 days, thus it is important to keep up a healthy intake. A few symptoms of a thiamine deficiency (knows as beriberi) include:
- Developing depression
- Pains in the abdomen
Pork tenderloin is also leaner than chicken making it a healthier source of protein.
Tuna has a very high omega-3 fatty acid content. Omega-6 (the unhealthy fatty acid) and cholesterol tends to build up in the blood vessels and arteries, increasing the risks of developing heart disease. Omega-3 strips away the Omega-6 fatty acids.
A single can of tuna yields up to 80 percent of the recommended daily dose of protein. Having protein in your body is pivotal to muscle development and growth. Protein is also responsible for quickening the rate at which wounds on the body heals after an injury.
The anti-inflammatory properties of tuna helps to lower hypertension and keep your blood pressure regular.
Tuna is full of a range of B vitamins. B vitamins are linked to improving your overall organ function and boosting your metabolism.B vitamins are also known to increase the amount of energy your body produces daily.
Tuna is very high in iron. Iron increases the amount of red blood cells in your circulation system and the actual volume of blood.
The sodium and potassium levels in tuna helps when it comes to managing the balance of fluid in your body. When there is a fluid imbalance in your body stress is put onto the kidneys and they are not able to function properly.
Cooked tuna produces peptides which are important for protecting cell membranes including those in the brain.
9. Beef Liver
Beef liver is very high in many different minerals and vitamins. One of these vitamins is vitamin B12. B12 is crucial to DNA synthesis, the formation of red blood cells and healthy neurological functions.
A vitamin B12 deficiency has been linked to multiple neurological disorders like dementia in older patients. Other B12 deficiency induced disorders include neuropathy (a disease that affects the nervous system), myelopathy (a disease that affects the spinal cord), disturbances to usual behaviour and overall weakening cognitive activity.
To get the most minerals and vitamins out of beef liver, be sure to buy hormone free.
Macular degeneration is a disease that affects the eyes. It is mostly prominent in the elderly. The more it progresses the higher the chance of permanent damage to the retina.
The fish oil in fatty fish increases the body's immune cell count which builds up a stronger immune system.
Sardines are high in the mineral selenium. Selenium goes directly into the nucleus of DNA cells and repairs any damage present. If this damage is not fixed the cell could become cancerous. Selenium has shown signs of cancer prevention, most notably liver, prostate and lung cancer.
Studies have pointed to selenium having a direct affect on the activity of the thyroid and the continued production of thyroid hormones. Your thyroid affects your weight, temperature, sleep patterns, appetite and energy levels.
Selenium is present in sperm mitochondria and very high or very low levels can have a negative impact on sperm count.
Low levels of selenium are prevalent in those suffering from chronic asthma.
11. Fortified Cereals
Cereals are complex carbohydrates that are enriched with vitamins and minerals. Fortified cereals range from oats to rye to rice.
Cereals provide a uniquely high level of energy. As cereals are so high inexpensive and calorie rich, they make up nearly 30 percent of calorie intake in North America and this percentage only increases in poorer countries.
Cereals contain both soluble and insoluble fibre. High fibre has many health benefits, such as keeping blood sugars at healthy levels and preventing disorders of the colon and constipation. When you eat, glucose is secreted into the body. Fibre slows this process down. Cereals improve the process of peristalsis (when the muscles in the intestines contract in such a way as to assist the movement of food within the digestive tract) and also increases the bulk of stools which keeps your system clean.
It is best to avoid cereals if suffering from celiac disease.
12. Fish Roe
Fish roe are fish eggs also known as caviar. Fish roe is another high omega-3 fatty acid food. Omega-3 reduces inflammation that is associated with many autoimmune diseases.
Fish roe also contain vitamin B12, magnesium, calcium and iron. Including foods high in magnesium can:
- Reduce anxiety and nervousness
- Prevent migraines
- Relieve muscles spasms and aches
- Increase your energy
- Aid digestion
- Regulate sodium levels
The potassium in mushrooms works as a vasodilator (something that widens the blood vessels which allows more blood to pass through) and relaxes tension within blood vessels. This results in lowered blood pressure.
Potassium is also responsible for better cognitive function because when blood vessels are relaxed and more oxygenated blood is flowing to the brain, higher levels of neural activity are stimulated.
Mushrooms contain copper which is a trace mineral. Copper increases the rate at which our bodies absorb iron which in key in avoiding developing anaemia. Copper also regulates your heartbeat and ensures that the body grows at a normal rate.
Copper can reduce the signs of ageing because it stimulates the production of collagen.
Mushrooms are a form of natural antibiotic that is very effective in protecting people with diabetes from developing infections in their arms and legs. They also support proper function of the pancreas, certain endocrine glands and the liver. They promote insulin formation and regulation.
14. Orange Juice
Just one serving of orange juice has over 200 percent of the recommended daily intake of vitamin C, or ascorbic acid. Vitamin C is a powerful antioxidant that protects the immune system against free radicals making it stronger and less susceptible to infection. Another important function of this antioxidant is keeping DNA of cells that are healthy from mutating and becoming cancerous. Vitamin C and ts antioxidant properties are the first line of defence against colds, flu and more serious diseases.
Orange juice has a very high folate content. Folate is most notably responsible for the growth of young cells and creating DNA. Folate is also important for creating more red blood cells and for promoting blood flow to your extremities.
The antioxidant hesperidin, which is found in orange juice, impacts the function and activity of the smaller blood vessels. Hesperidin can lower high blood pressure and significantly decrease your chances of developing heart disease.
Orange juice contains fibre which regulates bowel movements and can lower cholesterol levels.
The citrates and citric acid in orange juice can prevent the development of kidney stones. Kidney stones are solid mineral deposits that develop in your kidneys. They can cause debilitating abdominal and or side and back pain as well as urine in the blood.
15. Infant Formula
Infant formula is becoming the world’s most popular fortified food. While breast feeding is preferable some mothers are unable to (low milk supply, baby not latching etc) and are thus unable to pass on antibodies and nutrition to their babies. Infant formula is enriched with the minerals and vitamins babies need to grow and thrive.
Certain types of infant formula even have an added probiotic called bifidobacterium lactis which reduces the effects of colic (a condition where seemingly healthy babies cry for three or more hours per day), decreases the chance of developing food allergies and reduces diarrhoea.
Infant formula can also reduce allergies in babies.