Vitamin D: The Sunshine Vitamin
25 Feb 2023
Vitamin D is often referred to as the “sunshine vitamin”. This is because it is synthesized in our skin in response to sunlight. The beauty of Vitamin D is that it’s free – a great model for “all things in moderation” too.
There are two main forms of vitamin D: vitamin D2 and vitamin D3. Vitamin D3 is the form that is synthesized in the skin, while vitamin D2 is found in some plant-based foods and supplements.
Vitamin D plays a crucial role in maintaining bone health by promoting the absorption of calcium and phosphorus from the diet. It also helps to regulate the immune system and may reduce the risk of certain types of cancer, such as colon, breast, and prostate cancer.
Despite the importance of vitamin D, many people are deficient in this essential nutrient. In fact, studies suggest that up to 50% of the global population may have insufficient or deficient levels of vitamin D!
Symptoms of deficiency can vary, including fatigue, depression, cognitive decline and dementia. Bone density loss increases the risk of fractures and falls in older people. Low levels of vitamin D have been associated with increased risk of heart disease and diabetes.
Why does a deficiency develop? It can be difficult to get enough vitamin D from sunlight, especially during the winter months. Additionally, vitamin D is found in relatively few foods, so it can be challenging to get enough vitamin D from the diet.
Scientific studies have found income, gender and ethnicity differences in vitamin D status globally. One study looked at the vitamin D status of over 1,000 healthy Japanese adults and found that 40% of women and 26% of men had vitamin D deficiency and that individuals of non-Japanese ethnicity were more likely to have vitamin D deficiency than those of Japanese ethnicity. A study in the US found that people with higher incomes were more likely to be using supplements, and therefore less likely to suffer deficiencies. Consumer choices and food prices may also be important. Studies have found that consumption of fortified milk and mild products, or example, has a major effect on likelihood of deficiency.
If you need to know your vitamin D level, a blood test will determine it. But as the philosopher Voltaire once said, “the best is the enemy of the good.” Getting regular intake of Vitamin D should be the goal, not trying to measure daily levels.
Make it a habit to get some vitamin D everyday. The most effective way is to get sunlight directly on your skin. Spending 10-15 minutes outside in the sun each day with your arms and legs exposed will help your vitamin D levels, plus sunshine is a “feel good” prescription in general. Be sure to protect your skin with sunscreen if enjoying longer exposure.
But getting outside without layers of clothes can be difficult during the winter months, especially in northern latitudes. So don’t forget you also get vitamin D from certain foods include fatty fish (such as salmon, tuna, and mackerel), egg yolks, and fortified foods (such as milk, orange juice, and cereal).
If you’re not one for being in the sun and concerned the Vitamin D is your diet is insufficient, a daily supplement can help. The recommended daily intake of vitamin D varies depending on age, sex, and other factors, but in general, adults need between 600 and 800 international units (IU) per day.
The upper limit for vitamin D intake is 4,000 IU per day for adults, and it’s important not to exceed this amount unless under medical supervision.
