This Monday just passed was Blue Monday (January 20).
Blue Monday is the name given to a day in January (typically the third Monday of the month) claimed to be the most depressing day of the year. The concept was first published as part of a 2005 press release from holiday company Sky Travel, which claimed to have calculated the date using an equation. It takes into account weather conditions and this only applies to the Northern Hemisphere. By coincidence, the date in the United States almost always coincides with the celebration of Martin Luther King Jr. Day, a federal holiday, and so the concept of Blue Monday is not widely known there.
The idea is considered pseudoscience, with its formula derided by scientists as nonsensical.
But, it's an important date to note.
Some information on Vitamin D from Harvard Medical School:
Vitamin D Deficiency: A Global Concern
If you live north of the line connecting San Francisco to Philadelphia and Athens to Beijing, odds are that you don’t get enough vitamin D. The same holds true if you don’t get outside for at least a 15-minute daily walk in the sun. African-Americans and others with dark skin, as well as older individuals, tend to have much lower levels of vitamin D, as do people who are overweight or obese.
Worldwide, an estimated 1 billion people have inadequate levels of vitamin D in their blood, and deficiencies can be found in all ethnicities and age groups. Indeed, in industrialized countries, doctors are even seeing the resurgence of rickets, the bone-weakening disease that had been largely eradicated through vitamin D fortification.
Why are these widespread vitamin D deficiencies of such great concern? Because research conducted over the past decade suggests that vitamin D plays a much broader disease-fighting role than once thought.
Being “D-ficient” may increase the risk of a host of chronic diseases, such as osteoporosis, heart disease, some cancers, and multiple sclerosis, as well as infectious diseases, such as tuberculosis and even the seasonal flu.
Currently, there’s scientific debate about how much vitamin D people need each day. The Institute of Medicine, in a long-awaited report released on November 30, 2010 recommends tripling the daily vitamin D intake for children and adults in the U.S. and Canada, to 600 IU per day. (7) The report also recognized the safety of vitamin D by increasing the upper limit from 2,000 to 4,000 IU per day, and acknowledged that even at 4,000 IU per day, there was no good evidence of harm. The new guidelines, however, are overly conservative about the recommended intake, and they do not give enough weight to some of the latest science on vitamin D and health. For bone health and chronic disease prevention, many people are likely to need more vitamin D than even these new government guidelines recommend.
Vitamin D Sources and Function
Vitamin D is both a nutrient we eat and a hormone our bodies make. Few foods are naturally rich in vitamin D, so the biggest dietary sources of vitamin D are fortified foods and vitamin supplements. Good sources include dairy products and breakfast cereals (both of which are fortified with vitamin D), and fatty fish such as salmon and tuna.
For most people, the best way to get enough vitamin D is taking a supplement, but the level in most multivitamins (400 IU) is too low. Encouragingly, some manufacturers have begun adding 800 or 1,000 IU of vitamin D to their standard multivitamin preparations. If the multivitamin you take does not have 1,000 IU of vitamin D, you may want to consider adding a separate vitamin D supplement, especially if you don’t spend much time in the sun. Talk to your healthcare provider.
Two forms of vitamin D are used in supplements: vitamin D2 (“ergocalciferol,” or pre-vitamin D) and vitamin D3 (“cholecalciferol”). Vitamin D3 is chemically indistinguishable from the form of vitamin D produced in the body.
The body also manufactures vitamin D from cholesterol, through a process triggered by the action of sunlight on skin, hence its nickname, “the sunshine vitamin.” Yet some people do not make enough vitamin D from the sun, among them, people who have a darker skin tone, who are overweight, who are older, and who cover up when they are in the sun.
Correctly applied sunscreen reduces our ability to absorb vitamin D by more than 90 percent. And not all sunlight is created equal: The sun’s ultraviolet B (UVB) rays—the so-called “tanning” rays, and the rays that trigger the skin to produce vitamin D—are stronger near the equator and weaker at higher latitudes. So in the fall and winter, people who live at higher latitudes (in the northern U.S. and Europe, for example) can’t make much if any vitamin D from the sun.
How much vitamin D do I need?
The amount of vitamin D you need each day depends on your age. The recommended amounts, in international units (IU), are
Birth to 12 months: 400 IU
Children 1-13 years: 600 IU
Teens 14-18 years: 600 IU
Adults 19-70 years: 600 IU
Adults 71 years and older: 800
IUPregnant and breastfeeding women: 600 IU
People at high risk of vitamin D deficiency may need more. Check with your health care provider about how much you need.
What causes vitamin D deficiency?
You can become deficient in vitamin D for different reasons:
You don't get enough vitamin D in your dietYou don't absorb enough vitamin D from food (a malabsorption problem)You don't get enough exposure to sunlight.Your liver or kidneys cannot convert vitamin D to its active form in the body.You take medicines that interfere with your body's ability to convert or absorb vitamin D
Who is at risk of vitamin D deficiency?
Some people are at higher risk of vitamin D deficiency:
Breastfed infants, because human milk is a poor source of vitamin D. If you are breastfeeding, give your infant a supplement of 400 IU of vitamin D every day.Older adults, because your skin doesn't make vitamin D when exposed to sunlight as efficiently as when you were young, and your kidneys are less able to convert vitamin D to its active form.People with dark skin, which has less ability to produce vitamin D from the sun.People with disorders such as Crohn's disease or celiac disease who don't handle fat properly, because vitamin D needs fat to be absorbed.People who have obesity, because their body fat binds to some vitamin D and prevents it from getting into the blood.People who have had gastric bypass surgeryPeople with osteoporosisPeople with chronic kidney or liver disease.People with hyperparathyroidism (too much of a hormone that controls the body's calcium level)People with sarcoidosis, tuberculosis, histoplasmosis, or other granulomatous disease (disease with granulomas, collections of cells caused by chronic inflammation)People with some lymphomas, a type of cancer.People who take medicines that affect vitamin D metabolism, such as cholestyramine (a cholesterol drug), anti-seizure drugs, glucocorticoids, antifungal drugs, and HIV/AIDS medicines.
Talk with your health care provider if you are at risk for vitamin D deficiency. There is a blood test which can measure how much vitamin D is in your body.
What problems does vitamin D deficiency cause?
Severe vitamin D deficiency can also lead to other diseases. In children, it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend. African American infants and children are at higher risk of getting rickets. In adults, severe vitamin D deficiency leads to osteomalacia. Osteomalacia causes weak bones, bone pain, and muscle weakness.
Researchers are studying vitamin D for its possible connections to several medical conditions, including diabetes, high blood pressure, cancer, and autoimmune conditions such as multiple sclerosis. They need to do more research before they can understand the effects of vitamin D on these conditions.
How can I get more vitamin D?
There are a few foods that naturally have some vitamin D:
Fatty fish such as salmon, tuna, and mackerelBeef liverCheeseMushroomsEgg yolks
You can also get vitamin D from fortified foods. You can check the food labels to find out whether a food has vitamin D. Foods that often have added vitamin D include
MilkBreakfast cerealsOrange juiceOther dairy products, such as yogurtSoy drinks
Vitamin D is in many multivitamins. There are also vitamin D supplements, both in pills and a liquid for babies.
If you have vitamin D deficiency, the treatment is with supplements. Check with your health care provider about how much you need to take, how often you need to take it, and how long you need to take it.
Can too much vitamin D be harmful?
Getting too much vitamin D (known as vitamin D toxicity) can be harmful. Signs of toxicity include nausea, vomiting, poor appetite, constipation, weakness, and weight loss. Excess vitamin D can also damage the kidneys. Too much vitamin D also raises the level of calcium in your blood. High levels of blood calcium (hypercalcemia) can cause confusion, disorientation, and problems with heart rhythm.
Most cases of vitamin D toxicity happen when someone overuses vitamin D supplements. Excessive sun exposure doesn't cause vitamin D poisoning because the body limits the amount of this vitamin it produces.
Check out one of my current reads: Chasing the Sun, by Linda Geddes, on the Blinkist app or in stores for a comprehensive look at Vitamin D and its role in our health & well-being.