Vitamin D: Is It a Miracle? (Part 2)

Last week (in "Vitamin D: Is It a Miracle? [Part 1]"), we started to delve into the world of vitamin D. Many of you posted comments about your experiences with vitamin D and how much you’ve benefited from taking a vitamin D supplement.


Besides preventing rickets and osteomalacia, what can vitamin D really do for us? What’s the evidence supporting the claims that vitamin D can do more besides keep our bones healthy? Let’s take a look at what we know about this “sunshine vitamin.”

Osteoporosis is a disease of the bones. Bones become very weak and brittle and, if not treated, over time bones can break even with the mildest activity, such as bending over or coughing. Both men and women can be affected by osteoporosis (it’s not just a “woman’s disease”).

One key to preventing osteoporosis is building up enough bone mass in your younger years. Once you’re in your 30’s, you’ve pretty much reached your peak bone mass. After that, you start to lose some of your bone mass as time goes on. While calcium, of course, is vital for bone health, vitamin D plays a prominent role as well.

Vitamin D is needed to absorb calcium in the gut; without this vitamin, calcium can’t do its job of strengthening bones. In addition, vitamin D helps to regulate blood calcium levels and enhances calcium reabsorption from the kidneys. So, calcium and vitamin D work in tandem.

Vitamin D is so important for bone health that one of the drugs for treating osteoporosis, Fosamax (alendronate sodium), comes in a formulation called Fosamax Plus D. This medication contains 2,800 international units (IU) of vitamin D.

Muscle Weakness and Pain
If you’re deficient in vitamin D, you might experience muscle weakness and/or muscle pain. Since there are multiple reasons for muscle weakness, any muscle symptoms should be evaluated by a health-care provider. Muscle weakness in the elderly is cause for concern, as it puts the person at risk for falling (and that leads to a whole host of other problems).

A blood test can determine a person’s level of vitamin D, and low levels can easily be treated with vitamin D supplements. And adequate vitamin D intake can prevent problems from occurring in the first place. One study involving nursing home residents found that those taking 800 IU of vitamin D daily were 72% less likely to fall than those given a placebo.

Some research indicates that infants and children given vitamin D supplements are less likely to develop Type 1 diabetes. In one recent study published online in the Archives of Disease in Childhood, children who were given vitamin D were 30% less likely to develop Type 1 diabetes than those not taking a supplement.

It’s already well-known in diabetes circles that children living in areas of the world without much sunlight, such as Finland, have higher rates of Type 1 diabetes than those in in sunnier parts of the world. In fact, infants in Finland are 400 times more likely to develop diabetes than infants in Venezuela. Infants should receive 200 IU of vitamin D daily.

Vitamin D may also play a role in preventing Type 2 diabetes. One study, in the journal Diabetes Care, looked at data from 4,000 men and women. Vitamin D levels were significantly lower in the 187 people who developed Type 2 diabetes than in those who didn’t get diabetes. And those with the highest blood levels of vitamin D were 40% less likely to get diabetes.

Also, data from the Nurses’ Health Study found that women who took a combination of 1,200 mg of calcium and more than 800 IU of vitamin D daily had a 33% lower chance of getting Type 2 diabetes than women taking smaller amounts of these nutrients. The thinking is that both calcium and vitamin D play a role in glucose metabolism in the body.

Heart Attack and Stroke
Vitamin D really gets around—around the organ systems, that is. A study published in a January 2008 issue of Circulation, using data from the famous Framingham Heart Study, indicated that participants with the lowest blood levels of vitamin D were 62% more likely to have either a heart attack or a stroke than those with higher vitamin D levels. The results were so impressive that one of the study authors believes that people should take between 1,000 and 2,000 IU of vitamin D every day. (The jury is still out on the optimal dose of vitamin D.)

More on the wonders of vitamin D next week!

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  • CaroleLynne

    Great reporting – I also wanted to add that as a 15 year breast cancer survivor there is new research there that women at the time of their diagnosis if they had a Vitamin D deficiency did not do as well – so the unlocking of the key of this important vitamin is just beginning and very exciting. That being said I am 61 had my Endo had my levels drawn imagine my surprise that I was deficient. I was deficient enough that I had to be put on a loading dose to get my levels up and I will probably need high supplementation from now on. AFter 7 weeks my numbers are almost normal and one of the first things I noticed is my muscle aches and pains were lessened and my one arthritic finger was pain free. I can use it again without discomfort.

    Supplementation over recommended daily doses of course need monitoring my lab tests and your doctor but I feel 100% better and I feel that I have added protection for my heart now too. Funny thing I live in Florida and I do get sun exposure but obviously I was not storing it. Thank you for your column.

  • acampbell

    Hi CaroleLynne,
    Thanks for your posting and for sharing the information about the link between breast cancer outcomes and vitamin D deficiency. It’s interesting how many people are sharing that their blood vitamin D levels have been low – it seems to be more widespread than we all thought!

  • Hal

    Large studies in the US put the average serum 25(OH)D levels (stored vitamin d) at around 17.8 ng/ml. Many researchers in the vitamin d field now feel that target levels should be in the 40 to 60 ng/ml region. Some researchers feel that it should be even higher (the Vitamin D Console recommends 50 to 80 ng/ml). In northern areas of the US 97% of the population falls below the lowest of these levels and even in the south over 85% are below these levels. So the rate of deficiency is very high.

    For those cancers where vitamin d appears to be a factor (17 have been identified so far) the lowest levels of serum 25(OH)D that show a reduction in the cancer rate is 32 ng/ml which is almost two times the national average and some caners have declining rates up to 54 ng/ml. Researchers do not know where the upper limits of the cancer rate/vitamin d levels curve is because current populations do not have many individuals with levels higher than 55 ng/ml. For some of these cancers the reduction over 5 years in the cancer rate for vitamin d supplementation was as high as 77% (colon cancer – 1100 ui of vitamin d a day).

    Researchers working in the vitamin d field say that 97% of what they now know about vitamin d has been learned in the last 5 years and that the amount of research is increasing at an exponential rate. Current RDA for vitamin d dates from the early 1990s which predates all of the new research and it is clearly obsolete. The researchers are recommending 2,000 to 4,000 iu a day but also recommend blood tests to get the serum levels in the recommended range. They also recommend higher levels of supplementation in the winter months. Humans use about 5,000 ui a day. So depending on how much midday sun you get you will need to adjust your supplementation to compensate.

  • Ann Francis

    Very wonderful advice regarding preventing deadly diabetes as far as possible. It has become a real disaster in today’s time effecting old and young alike and if such preventive measures can really aid to save people from it than nothing could be more helpful.

  • Speaking of vitamin D, it functions a specific way in your body that researchers have considered it a hormone. It is involved in an important task known as the mineral homeostasis that deals with the regulation of the gene expression and also that of cellular differentiation.