Deficiency or Lack of Vitamin D, Why does it Happen?

Deficiency or Lack of Vitamin D, Why does it Happen?

Vitamin D is not a common vitamin since it can be obtained in different ways: through the diet and by sunbathing (UVB rays). It is an element that activates when our body needs it.

Up to a 90% of vitamin D is produced in this way. Only between a 5 and 10% of the vitamin D requirements are supplied through the diet, mainly through fatty fish, butter, milk, egg yolk, and cheese.

Several medical studies have proven that approximately between an 80 and 90% of the those who live in industrialized and modern countries suffer from a mild to severe vitamin D deficiency. The reasons why a vitamin D deficiency can occur are varied and can be related to a specific lifestyle and environment. It can also be due to a single factor or a combination of them.

The most common causes of a vitamin D deficiency are:

Not getting enough sunlight during the winter

This tends to happen to all those who live above the 42nd latitude (north of Rome). The sun is too low in these areas from October to March and it does not produce enough UVB radiation to go through our skin.

Going for a walk for 20 minutes in winter can be a well-intentioned advise, but it is not enough to produce vitamin D. Additionally, the environmental pollution of cities prevents the UV rays from reaching our skin.

Generally speaking, the vitamin D reserves that have been acquired during summer will run out and they drop to a half in approximately two months. Therefore, this issue affects a lot of people, and it makes them more likely to catch a cold, or to feel low or in a bad mood. A two-week winter holiday would be ideal to recharge our vitamin D levels in our body.

Causes of a Vitamin D deficiency

Very little sunbathing during the summer

Sunbathing in a swimsuit for 15-20 minutes, three times a week, is enough to keep the Vitamin D levels normal. However, this is not something that everyone can do, due to different reasons. This is why there is a lot of people who do not sunbathe enough during the summer.

In fact, it is advisable to sunbathe in the summer, no matter which latitude you live in.

Staying inside all the time (due to work)

Those who have a job that makes them stay in closed spaces or to work at night cannot get enough vitamin D. Moreover, this gets worse if their skin is also covered by clothes on their way to work.

Spending a lot of time watching the tv or computer is a fact that prevents a lot of people from sunbathing during the summer. This risk is very high, especially for those who live in big cities, where the chances of sunbathing are even more limited.

To these circumstances we have to add the fact that during the winter months we do not sunbathe as much. This is the most common reason why so many people suffer a vitamin D deficiency in big cities.

An excessive use of sunscreen

Nowadays, we are constantly being warned about the risk of suffering skin cancer or premature aging if we expose our body to direct sunlight. But this warnings usually prevent us from sunbathing, which then results in a vitamin D deficiency.

Even an 8 factor sunscreen will block the production of vitamin D in the dermis in a 95%. The ideal way to proceed would be to sunbathe without sunscreen only the first 10-30 minutes. This period of time should be adapted according to individual skin types. We must choose a proper period of time in order to prevent the onset of erythema.

Sunscreen must be used to avoid sunburns. If you want to stay in the sun for longer without protection, you can increase the exposure as you get more tanned.

Vitamin D deficiency in the diet

Food sources of vitamin D

Perhaps the foods that you consume have a very low amount of vitamin D. Some of the richest sources of vitamin D are:

  • 250-300 micro-grams in cod liver oil
  • 8-25 mcg in smoked eels and herring
  • 16 mcg in salmon
  • 4 mcg in mackerel
  • 3.8 mcg in beef
  • 1.7 mcg in beef liver
  • 2.9 mcg in eggs (total)
  • 1.2 mcg in butter
  • 2.5 to 7.5 mcg in margarine enriched with vitamin D
  • 1.3 mcg in Gouda cheese
  • 0.19 mcg in cottage cheese (40% of fat)
  • 0.06 to 0.09 mcg in whole milk and yogurt (3.5%)

These amounts are found in 100 grams and not all of these products are consumed in the same amounts. Cod liver oil has a very high amount of vitamin D, but its consumption provides very low quantities of Vitamin D.

On the other hand, the consumption of fatty fish in our latitudes is usually very low. Egg yolks, butter and cheese are frequent in our daily diet, but they are consumed in small quantities on a daily basis. However, they are one of the foods that most vitamin D provides to the body.

Vegans particularly have a higher risk of suffering from a vitamin D deficiency, because this vitamin tends to be found mainly in foods of animal origin. Although fungi and avocados have Vitamin D2, the precursor form of vitamin D.

However, it must be transformed into vitamin D, a process carried out by the sunlight on the dermis.

With a bit of effort one can reach the recommended daily amount of 5 mcg (200 UI). However, this amount is not enough to produce or keep healthy Vitamin D levels in the body.

The consumption of medications or alcohol

Antidepressants, blood thinners, steroids and medications to treat peptic ulcer disease and epilepsy can inhibit the absorption of the vitamin D from our diet. Even those who drink a lot of alcohol may have a higher risk of developing a disease related to a vitamin D deficiency. They should consume vitamin D supplements.


People with obesity have a lower ability to produce vitamin D when compared to those who are not overweight. Medical studies have proven that obese people have, in most cases, lower levels of vitamin D 25(OH)D that thin people.

Being overweight is goes hand in hand with being less exposed to the sunlight and a reduced diet.

Old age

As we age, our body progressively loses the ability to synthesize vitamin D from the sun. At the same time the need to obtain vitamin D increases.

Once we pass the age of 65, the skin produces half of the amount of vitamin D when compared to a young person. On the other had, old people tend to go outside less, and for this reason their body produce less vitamin D.

Being bedridden or suffering from a disability

Those who are bedridden or who have difficulties to walk tend to develop a vitamin D deficiency quickly. Moreover, they usually have less appetite and therefore eat less foods with vitamin D. Thus, it is advisable for them to use vitamin D supplements.

Vitamin D deficiency caused by diseases

Those who are sick or ill have an increased difficulty to obtain vitamin D through their diet or sunbathing. They spend most of the time inside due to the disease, a lack of motivation and, in the worst cases, depression. Therefore, sunbathing is not an activity that they normally carry out, and they will inevitably develop a vitamin D deficiency. This will only worsen the state of the disease.

People with dark skin

People with dark skin have more melanin. This pigment prevents the sun rays from penetrating the dermis, which considerably reduces the production of vitamin D.

For this reason, those who have a dark skin have to sunbathe longer than those with light skin, in order to obtain the same amount of vitamin D.

When people with dark skin live in northern latitudes, they can end up suffering a vitamin D deficiency. If they cannot consume dairy products either, due to a congenital lactose intolerance, the supply of this vitamin through the diet is significantly reduced.

Have you experienced one or several of the risks that we have described for more than three months? If so, it is possible that you may be suffering a vitamin D deficiency.

In general, it is not possible to change the lifestyle nor living somewhere where there is sunlight throughout the whole year. That is why taking a vitamin D dietary supplement is the best choice to have proper vitamin D levels.

Who has more chances of suffering a Vitamin D deficiency?

  • Those who live north of the 42nd parallel
  • Vegetarians and vegans
  • Those who always use sunscreen (with a protection factor of 8 or higher)
  • People who live in big cities, regardless of the latitude
  • Alcoholics
  • Those who spend a lot of time indoors (those who work indoors, the chronically ill, physically disabled, prisoners)
  • Obese or overweight people
  • Dark-skinned people
  • Those who work at night
  • People who need to take certain medications
  • Children under 1 year old born in autumn-winter
  • Pregnant women
  • If you want to purchase vitamin D supplements you can click here and visit our online store.
Sunbathing in different parts of the world

Conclusion: The further away you live from the equator, the darker your skin is, the more obese you are, and the less you sunbathe, the more vitamin D you should consume. It does not matter if it is through the diet or as dietary supplements. It is important to be able to keep healthy levels of this vitamin in the blood.

How to detect a Vitamin D Deficiency?

The symptoms of a lack of vitamin D in the blood are different and this deficiency will become more severe if they are prolonged in time.

The first symptoms are:

  • Fatigue and tiredness
  • Pessimism and low mood
  • Languor
  • Nervousness
  • Mild excitability
  • Insomnia
  • Craving for sweets
  • Muscle weakness
  • Myopia
  • Cavities and gingivitis

The following symptoms can be reversed with the right intake of Vitamin D:

  • Rickets in children
  • Osteomalacia (softening of bones)
  • Osteoporosis (fragile bones)
  • Skeleton-muscle pain
  • Susceptibility to allergies
  • Infections of the respiratory tract
  • Organic pain

If the lack of vitamin D in the blood persists, it can cause the following symptoms:

  • Autoimmune diseases
  • Rheumatism and degenerative disorders
  • Personality changes
  • Bone fractures
  • Reactions to food and objects of daily life
  • Errors in physical functioning

This symptoms can be fixed with an adequate treatment.

Recent medical studies suggest that a vitamin D deficiency in the blood is related to the onset of:

  • Cardiovascular diseases
  • Arteriosclerosis
  • Fibromyalgia
  • Psoriasis
  • Muscle weakness
  • Premenstrual syndrome
  • Back and bone pain
  • Hypertension
  • Type I Diabetes
  • Multiple sclerosis
  • Alzheimer’s disease
  • Rheumatoid arthritis
  • Cancer
  • Etcetera

This does not mean that these diseases are exclusively due to a vitamin D deficiency. However, the researchers believe that a lack of vitamin D is a decisive factor that will contribute to its development and that a proper consumption of vitamin D can lower the risk of suffering these pathologies.

Related Entries:

Vitamin D Deficiency Review

Causes - 100%

Risks - 100%

Detect a deficiency - 100%

Related Studies - 99%


HSN Evaluation: 5 /5
Content Protection by
About Melanie Ramos
Melanie Ramos
Melanie Ramos uses the HSN Blog to share the latest information and content, so that all those readers who want to learn.
Check Also
Benefits of Vitamin D
9 Benefits of Vitamin D

The “Sunshine Vitamin” is one of the best allies for your health. Nevertheless, there are …

Leave a Reply

Your email address will not be published.