You may have noticed in recent years that vitamin D is suggested to be the cure all for everything. Then recently it was found to not be the miracle vitamin it was thought to be. In this article I explain what vitamin D is and where it is important for midlife women.
What is Vitamin D?
Vitamin D is actually not a vitamin. It is actually a substance that the body converts into a hormone. Our bodies create the hormone from sunlight through the liver and the kidneys. It is known as the sunshine vitamin. Vitamin D also comes from a few foods and can be obtained through supplements.
Vitamin D is fat soluble which means that your body stores the vitamin in fat. You don’t need to get it every day like water soluble vitamins.
Why do you need vitamin D?
Vitamin D has several functions in the body. There are many reasons why understanding vitamin D is important for midlife women.
- It helps with calcium absorption and keeping blood calcium levels balanced.
- Your bones require vitamin D to absorb calcium and phosphorus from foods you eat. Low vitamin D levels are associated with osteoporosis and with rickets.
- Low vitamin D levels are also linked to cancer, heart disease, autoimmune diseases, high blood pressure, and obesity
- Vitamin D supplementation may reduce the risk of cancer
Is the hype valid?
I remember a few years ago when people thought that vitamin D could cure everything from the common cold to cancer. However studies with supplemental vitamin D do not seem to reduce the risk of these diseases. Although low vitamin D levels are not good, just adding a vitamin D supplement might not be enough to solve everything. Vitamins and minerals work together in the body and all the interactions are not understood.
One example of this is that calcium metabolism also requires vitamin K. So a mega dose of vitamin D without vitamin K doesn’t help. In general, we don’t know enough about how everything interacts.
Where can you get vitamin D
The main source of vitamin D is sunlight. But many people in the northern hemisphere do not get enough sunlight especially in the winter months to reach that goal. Even if spend time outdoors the angle of the sun between October and April means that not much vitamin D is available from sunlight.
Vitamin D comes in 2 forms – D2 and D3. Vitamin D2 is found in mushrooms, fortified foods and supplements. Oily fish and fish oil, liver, egg yolk, butter and supplements contain vitamin D3. Vitamin D3 is the form that your skin produces.
Do you need to supplement?
If you live in a northern climate or spend very little time outdoors, then you will probably not get enough from sunlight for much of the year. In these cases a vitamin D supplement is usually recommended.
My best advice is to get your vitamin D levels tested and follow the advice of your physician about supplements. And take the advice of your physician for the dose of the supplement. The current US and Canadian recommendation is between 400 and 800 IU, but many experts recommend more. A supplement of up to 4000 IU is considered safe, but the best dose for you depends on several factors including age, where you live, and skin tone.
As you get older you don’t absorb vitamin D as well so you need to get more. And you want to make sure you are getting enough to help to keep your bones strong. Since I’m over 50, I live in Canada, and my vitamin D levels have been low in the past, I do supplement with vitamin D.
If you decide to supplement then vitamin D3 is a better choice than D2. Vitamin D2 may degrade quicker than D3 and vitamin D3 seems to be more effective at raising the levels of calcifediol, the form of vitamin D found in the blood.
Can you get too much vitamin D?
Because vitamin D is stored in the fat of the body, it accumulates over time. Vitamin D toxicity is possible, but not very likely unless you are taking a high dose supplement on a regular basis.
Vitamin D toxicity will not occur from sunlight or from food, but if you are taking high dose supplements you could possible experience some of the side effects:
- Elevated blood levels of vitamin D can lead to fatigue, forgetfulness, nausea, and vomiting
- High blood calcium levels which can cause vomiting, frequent urination and confusion
- Bone loss – very high vitamin D levels can cause the body to pull calcium from the bones into the blood
- Kidney failure
Vitamin D is important for health. Although some of the benefits may be exaggerated, it is clearly a vitamin we want to make sure we get enough of.