Winter blues got you down?
Vitamin D deficiency could play a part.
Vitamin D is a fat-soluble vitamin found naturally in very few foods. In fact, fortified foods with added vitamin D provide most of the vitamin D in the American diet.
What does vitamin D do?
Most people know that vitamin D has an important role in maintaining bone health in the body. It does so by helping the body absorb calcium. This is why some people who get too little vitamin D may develop thin or brittle bones.
However, vitamin D is also important for other things! Your immune system, muscles, heart, lungs and airways, and brain also need it. It may also help protect against osteoporosis, certain cancers, high blood pressure, and other diseases such as diabetes, Alzheimer’s and autoimmune diseases.
Where can I get vitamin D?
- Fatty fish such as salmon, tuna and mackerel are the best sources, as well as cod liver oil (which also contains a high amount of vitamin A)
- Egg yolks, cheese, and beef liver provide a smaller amount
- Milk – almost all milk in the US is fortified with vitamin D, but not all foods made from milk (ice cream, cheese)
- Fortified foods such as breakfast cereals, yogurt, margarine, orange juice, non-dairy beverages, infant formula, etc. (check the label)
- Supplements – either as D2 (ergocalciferol, from yeast or fungus and therefore vegan-friendly) or D3 (cholecalciferol, from an animal source)
… but that’s not all!
Your body makes it’s own vitamin D when it is directly exposed to the sun (UV light). That means no sunscreen, no clothing, and not through a window pane. And, yes, tanning beds will work as well. However, due to the risk of skin cancer, it’s important to limit this exposure to sunlight and tanning beds.
Did you know…
One study found that beta-endorphins increase after sun exposure,
and endorphins make you feel good!
Deficiency is a major problem
… and we aren’t talking about it enough
Recent studies have shown a high prevalence of vitamin D deficiency in those with seasonal affective disorder (SAD), depression, and psychiatric disorders such as schizophrenia.
Vitamin D deficiency is a worldwide problem affecting as many as 1 billion people.
Depression can vary in severity. You may feel low in spirits but are able to go about your everyday life, though it may feel less enjoyable and more of a challenge. In other cases, it may lead to a complete inability to function, low energy, impaired concentration, decreased interest, and suicidal ideations. It can come on gradually and may go unnoticed for quite some time.
It’s also more common than you think.
In the US, about 1 in 10 people have depression, and 1 in 3 cases will be severe. There is also a strong genetic connection and can be triggered by any number of things, such as major life changes (divorce, relocation, death), illness (cancer, diabetes, arthritis), individual personality traits, or personal circumstances.
Connect the dots for me here…
Why even bother mentioning all of this?
Vitamin D receptors have been found in the brain on the surface of cells where they receive chemical signals. This means that vitamin D itself is acting in some way on the brain.
Exactly how this works is not yet understood. One theory is that it affects the amount of chemicals, such as serotonin and dopamine, and how they work in the brain. Many antidepressants (SSRIs) work by increasing these kinds of chemicals in the brain.
What does the research say?
Unfortunately, it is only recently that large-scale studies have been done focusing on this link and lack of uniform dosages, parameters, populations, measurement tools, and administration are just a taste of why we may be getting mixed results. Due to this variability, it is hard to say with certainly what role vitamin D has with respect to mental health.
There are a few strong studies from recent years that have shown there is a relationship between low levels of serum (blood) vitamin D and depression.
However, we do not know if vitamin D deficiency is the cause or an effect of depression.
Lack of vitamin D may be just one of many factors that contribute to mood and may take a long time to take effect. People who are depressed usually go outside less, and so are less likely to have had adequate sun exposure to make their own vitamin D. They are probably also less likely to be taking care of themselves with respect to nutrition and proper supplementation when needed.
Currently, the majority of prescribers are not considering vitamin D supplementation as a preventative measure in the psychiatric population. Most commonly it is only prescribed for those with osteoporosis and vitamin D deficiency.
Symptoms of deficiency
These can be vague, such as feeling tired and achy. You may get sick more often. Some have no symptoms at all!
The only way to know for sure is to see your physician or get your blood tested for vitamin D levels (specifically, your serum 25(OH)D level),
Who is at risk?
- People with limited sun exposure – whether that be due to working a job that is largely indoors, wearing sunscreen, wearing long sleeves and pants, being homebound, work nightshift, or living in an area with weather that is largely overcast.
- People with dark skin – extra pigment in the skin reduces its ability to produce vitamin D from sunlight. It can take up to 6x longer for someone with dark skin to make the same amount of vitamin D as someone with very fair skin.
- Elderly – older people have thinner skin and also usually spend more time indoors.
- Pregnant women – their bodies need more vitamin D than usual.
- People with fat malabsorption disorders – such as inflammatory bowel disease (IBD, Crohn’s disease, ulcerative colitis), cystic fibrosis, and some forms of liver disease.
- Those who are obese or have had gastric bypass weight loss surgery – as a fat-soluble vitamin, it is stored in fat stores in the body, which will be used as the person loses weight if they are not taking in enough through diet and supplementation. Also, part of the intestine where vitamin D is absorbed is no longer able to be used after bypass surgery. Those who are obese (defined as a body mass index > 30) may have higher vitamin D requirements.
- Breastfed infants – vitamin D drops are sold and can be added to pumped breastmilk for this reason.
- Those taking some prescription medications – such as prednisone and other corticosteroids, epilepsy drugs (such as barbiturates, carbamazepine, and phenytoin), some HIV medications, and some weight-loss and cholesterol-lowering products (such as orlistat and cholestyramine) can alter vitamin D absorption and/or metabolism.
How much do I need?
Different organizations have different recommendations for what is considered an ‘ideal’ vitamin D level.
The Vitamin D Council says that 50 ng/mL (125 nmol/L) is ideal, whereas the Food and Nutrition Board under the Institute of Medicine, which sets the Dietary Reference Intakes (DRIs), says that 20 ng/mL (50 nmol/L) is generally considered to be adequate for bone and overall health in healthy individuals.
This translates into 5,000 IU/day of vitamin D supplementation for adults in order to reach and maintain the level set by the Vitamin D Council and only 600 IU/day for the level set by the Food and Nutrition Board. For sun exposure, a good rule of thumb is about half the time it would normally take for your skin to turn pink, which can depend on time of day, time of year, air pollution, altitude, weather, and geographic location.
If you test below the recommended level, you may want to get more sun exposure or take a larger daily supplement (preferably in the form of D3). Keep in mind that you will probably get more sun exposure in the summer than the winter, so you may need to supplement more in the winter. Retest and check every 3-6 months if you are trying to change your vitamin D level.
More is not always better! In general, you do not want to have a level over 100 ng/mL (250 nmol/L) and anything over 150 ng/mL (375 nmol/L) is considered toxic. Because of vitamin D’s potential to be stored in fat tissues, risk of toxicity should not be ignored.
Talk to your doctor!
Some individuals may need to take extra care when it comes to taking vitamin D supplements:
- Those taking digoxin for atrial fibrillation or thiazide diuretics such as hydrochlorothiazide or bendroflumethiazide
- Certain medical conditions such as primary hyperparathyroidism, non-Hodgkin’s or Hodgkin’s lymphoma, kidney stones, a granulomatous disease, and some kidney, liver, or hormonal diseases
- If you have high blood calcium levels
If you have depression and want to take vitamin D, it is unlikely to make your symptoms worse, however, you may also not see any improvement in your symptoms. Also, you should not take vitamin D in place of other treatments or antidepressant medications.
If nothing else, depression should at least be considered a risk factor for osteoporosis.