Researchers believe that vitamin D plays a key role in maintaining health. If you live in the northern hemisphere, chances are you don't get enough vitamin D. The same is true if you don't get outside for at least 20 minutes per day exposing your face and arms. Those with dark skin, as well as the elderly have been shown to have lower levels of vitamin D.
What is Vitamin D?
Vitamin D is principally known for the role it plays in bone health. It helps with the absorption of calcium and phosphate, reduces calcium loss from bones, and is needed for bone growth and remodelling.
Being vitamin D deficient may increase the risk of a number of chronic diseases. These include osteoporosis, heart disease, multiple sclerosis, seasonal flu.
How much Vitamin D to boost immune system?
There is currently scientific debate about how much vitamin D people need each day. If the ideal amount of sun exposure can't be reached, vitamin D from dietary sources and supplements is recommended in order to prevent deficiency.
- At least 600 IU (15 µg) per day is recommended for people aged under 70
- 800 IU (20 µg) per day is recommended for those aged over 70 years
A safe upper maximum for adolescents and adults is 4000IU per day. Long-term amounts over 10,000IU per day have been associated with kidney damage.
What are the best sources of Vitamin D?
Vitamin D occurs in two forms namely D3 and D2. The main source of vitamin D comes from exposure to sunlight, when a steroid in the skin, called 7-dehydrocholesterol (7-DHC) is converted to vitamin D3 (cholecalciferol) through the action of the sun's UVB radiation.
Smaller amounts of vitamin D3 can also be obtained from certain foods such as fatty fish, eggs, meat and fortified foods such as margarine and certain low-fat milks.
Vitamin D2 (ergocalciferol) comes from fungi, and may be used in supplements. However, most Vitamin D2 is considered less potent than vitamin D3.
In addition to getting enough sun, it's important to eat the recommended dose of calcium as well as undertaking weight-bearing or muscle-strengthening exercises for optimal bone and muscle function.