Our bodies can obtain vitamin D both from our diets and from sun exposure – this we know. But even with these two routes for obtaining vitamin D, inadequate vitamin D is common and deficiencies can be found on all continents, in all ethnic groups, and across all ages.
Just about everyone feels better when the sun shines. This shouldn’t be so surprising since we are, in effect, solar powered, relying on plants to store the sun’s energy in carbohydrate, the body’s primary fuel. The sun’s energy is also stored as vitamin D and essential fats, both found richly in cold-water oily fish. For most of us today, the decline in oily fish consumption, which is largely due to fat phobia created by the popularity of low-fat diets, has fuelled an epidemic of both emaga-3 and vitamin D deficiency. Interestingly and contrary to what you may think, the darker your skin and the further you live from the equator, the greater the risk will be of vitamin D deficiency. People who have a darker skin tone have more melanin in their skin, and this pigment is a “natural sunscreen” that slows down skin production of vitamin D. This the main reason why many darker skinned South Africans are more likely to be low in vitamin D, than they realise.
There is a growing body of research that not only links low vitamin D levels in the blood to a higher incidence of depression, but it also links them to premenstrual syndrome and seasonal effective disorder (known as SAD). The research shows that supplementing vitamin D also improves mood.
Seasonally, one of the reasons we feel “blue” in the winter, according to research from the Baker Heart Institute in Melbourne, is that serotonin levels in the brain are lowest in the winter and the amount of serotonin our brains produce is directly related to how much daylight we are exposed to. So, with shorter days and less light, people with SAD can really suffer. Some people, especially women, are prone to low levels of serotonin anyway, and a relative lack of light can tip them over the edge into depression. But there is another reason, and that is lack of vitamin D. This vital mood-boosting vitamin is made in the skin in the presence of sunlight, and many of us, especially in the winter, don’t make enough.
Vitamin D is not only vital for the brain, nervous system and immune system, with profound anti-cancer effects, it is also vital for healthy bones. The importance of vitamin D, beyond its role in bone health, came to be noticed when researchers investigated possible reasons why the prevalence of a number of disease, including many forms of cancer, MS and schizophrenia, increases in relation to distance from the Equator.
Here’s what to do for a natural mood boost:
- Expose your skin to sunlight for 30 minutes a day with at least your face and arms exposed. Be careful not to burn your skin.
- If you are prone to feeling low in winter, invest in some full-spectrum lighting and extend the length of you light exposure.
- Take a daily multivitamin that provides you with 15mcg of vitamin D and during winter, 25 to 30mcg of vitamin D.
- Eat oily fish (fresh or canned or smoked salmon, mackerel, herring, kippers, sardines) which are rich in vitamin D, at least three times a week and especially in winter.
- Build exercise into your daily routine, for at least 20 minutes a day, preferably outdoors.