Feature Articles: Eating Well
Vitamin D does more than help utilize calcium
Tammy Roberts, MS, RD, LD, Nutrition and Health Education Specialist, University of Missouri Extension
As many people know, vitamin D is added to milk to help our bodies absorb and utilize calcium to keep our bones and teeth strong and healthy. What many people do not know is that vitamin D has been successfully used to help treat psoriasis and muscle weakness among other things. A study from Creighton University at Omaha, Nebraska revealed that vitamin D can also reduce the risk of cancer in postmenopausal women.
Vitamin D has been called the sunlight vitamin because the human body can actually make its own vitamin D after exposure to the sun. The UV rays from the sun are the very thing most of us are trying to avoid when we are outside, but they are what the body uses to make vitamin D. Sunscreens with SPF of 8 or above will block the UV rays that help us make vitamin D. Not to worry though because you only need 10-15 minutes of sun exposure on the face, arms and hands twice per week to allow for vitamin D synthesis. Vitamin D is a fat-soluble vitamin, which means that our bodies are able to store and then utilize that vitamin, so you don’t have to have daily sun exposure in order to get enough vitamin D.
It is especially hard to get 10-15 minutes of sun in the winter or in long periods of overcast skies so it’s important to know the sources of food that provide vitamin D. As mentioned, vitamin D is added to milk so it is a good source. Vitamin D is not added to other dairy products such as ice cream and cheese. Cod liver oil is a great source of vitamin D providing 1,360 International Units (IU) per tablespoon; 3½ ounces of cooked salmon provides 360 IU; 3 ounces of tuna fish canned in oil provides 200 IU; cereals fortified with 10% of the Daily Value for vitamin D provides 40 IU and one egg provides 20 IU. One cup of fortified milk provides 100 IU of vitamin D.
How much vitamin D do you need? The Institute of Medicine has established an Adequate Intake (AI) for vitamin D. Adequate Intake in the case of vitamin D represents the daily intake that should maintain bone health and normal calcium metabolism in healthy people. The AI for all people birth to 50 years is 200 IU per day. Adults ages 51-70 need 400 IU per day and adults over the age of 71 need 15 IU per day. The reason for the increased need after the age of 50 is that as we age we have more difficulty making our own vitamin D from exposure to the sun.
So, go ahead and take a little break to sit out in the sun for a few minutes and sip on a glass of milk. Your body will reap all of the benefits.
Last update: Friday, January 22, 2016