Winter has really arrived, lots of snow and freezing temperatures. Days are short and sunlight is rare. This lack of sunlight can affect our mood and our health.
One problem with the cold weather and cloudy days is our minimal exposure to sunlight. This is a health concern since almost all of the vitamin D in our bodies comes from exposing our bare skin to the sun. Most foods only contain small amounts of vitamin D. The exception to this is cod liver oil, which contains 680 units of vitamin D per ½ tablespoon. That’s great to know but, truthfully, who will take ½ tablespoon of cod liver oil daily?
The other problem with cod liver oil besides the taste is that it contains very large amounts of vitamin A and excessive vitamin A can be toxic.
Other foods with naturally vitamin D are:
- Fish (Salmon 360 units in 3.5 oz.; Mackerel 345 units in 3.5 oz.; Tuna, canned in oil 200 units in 1.75 oz.; Sardines 250 units in 1.75 oz.)
- Milk Vitamin D fortified (nonfat, reduced fat and whole) 1 cup has 98 units
- Egg, 1 whole (Vitamin D is in yolk) has 20 units
- Liver, beef 3.5 oz. has 15 units
- Ready-to-eat cereal, fortified 1 cup has 40 units
So how much vitamin D do we need to stay healthy?
Here are thelatest recommendations for daily vitamin D intake:
* Infants: 400-600 units
* Children: 600-1000 units
* Adults: 600-1000 units (some experts recommend even higher amounts)
The Vitamin D Council recommends taking the vitamin D3 form rather than vitamin D2.
Vitamin D3 is the type of vitamin D that our bodies produce in response to sun exposure while vitamin D2 is not.
So, why do we need vitamin D? Most people know that vitamin D is essential for strong bones. There is also some evidence that deficiency in vitamin D causes poor growth, fatigue and irritability. More recently, associations have been made with vitamin D deficiency and Type 2 diabetes, some cancers and rheumatoid arthritis. Vitamin D deficiency might also be a factor in autoimmune disease. Research is ongoing in these areas.
Are there instances when a person should not take vitamin D? Yes. Patients taking certain heart medication and hypertension medication should check with their physician before starting vitamin D supplements since these medications might interact with vitamin D. Other conditions where vitamin D might be a problem include, certain cancers, kidney disease and high blood calcium levels.
In summer it might be possible to make adequate amounts of vitamin D just by sun exposure. The amount of time necessary to generate 600 units of vitamin D varies by skin type and location as well as amount of skin exposed. Very fair skinned people need less sun exposure to make the same amount of vitamin D as dark skinned people. The general rule is to get half the sun exposure it takes for your skin to turn pink. So, if your skin becomes pink after 20 minutes in the sun then 10 minutes is enough time to get a good dose of vitamin D. Sunscreen is still necessary to avoid sunburn. It’s important to use common sense to get the right amount of sun exposure (and vitamin D) without injuring your skin.
Article written by Sue Gaston, M.D.