Vitamin D is known as the sunshine vitamin because it is made in the skin during exposure to sunlight. If you live in Ontario (or anywhere above the 37th parallel), it is impossible for your body to make enough vitamin D from mid-September to mid-May.
Vitamin D activates the immune system by “arming” T cells to fight off infections. Your immune system won’t function unless it is biochemically activated with vitamin D. If you’re facing the winter flu season in a state of vitamin D deficiency, your immune system is essentially defenceless against seasonal flu.
Feeling blue? Vitamin D can help. There are a large number of vitamin D receptors in the hypothalamus and hippocampus of your brain. With sufficient vitamin D, these receptors help to release dopamine, a neurotransmitter which aids in motivation and feelings of enjoyment.
Want to top up your vitamin D levels? Supplement with 2000 – 5000 IU of Vitamin D3/day. Vitamin D is a fat soluble vitamin so for best absorption, take it with your fish oil or a fat containing food. During the winter months try to increase your consumption of foods high in vitamin D3 such as cod liver oil, egg yolks, butter, organic beef liver and oily fish such as mackerel, salmon, sardines and herring.