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Vitamin D - Not Just for Bones Anymore

New info about vitamin D, the “sunshine vitamin”, is reported almost daily increasing our understanding of the importance of this fat-soluble nutrient. D is commonly used to prevent the deficiency bone disease called rickets. We now know that vitamin D has receptors in almost every cell in the body: Thus making it important for much more than was originally thought.

Vitamin D acts like a hormone relaying chemical messages. A deficiency of vitamin D may play a role in cancers, auto-immune diseases such as multiple sclerosis, type 1 diabetes, and rheumatoid arthritis. Additionally, mood disorders, autism, chronic pain, muscle weakness, type 2 diabetes, osteopenia, osteoporosis, infections, obesity and cardiovascular disease have all been linked to low levels of vitamin D. 

Vitamin D is made from exposure to sunlight. It is found in limited amounts in foods: oily fish such as salmon and mackerel, cod liver oil and egg yolk. To prevent rickets, foods such as milk, orange juice, cheese, cereal and breads have been fortified with D. Unfortunately, because of our fear of exposure to sunlight and skin cancer very low levels of vitamin D appear to be common in the population. Even rickets is making a comeback. 

The Institute of Medicine currently recommends the following intake of D: 

·         200 IU daily for adults up to age 50

·         400 IU daily for adults 51 to 70 years of age

·         600 IU daily over 70 

However, these doses do not maintain adequate D levels and debate is currently going on about how much higher recommended doses should be. In the past many cautioned about an excess of vitamin D since it can be stored and a risk of toxicity was feared. Now it is thought that doses up to 10,000 IU are likely to be safe. With sun exposure the body will manufacture thousands of units of vitamin D safely. But is D taken as a supplement as safe as that made in the body? No one knows that answer. 

Who needs more Vitamin D? 

Almost everyone it seems. To avoid deficiency and rickets the American Academy of Pediatrics recommends that children from infancy through the teen years get 400 IU of D each day- double the previous recommendation. This is especially true for infants that are exclusively feed breast milk because their mothers are often deficient in vitamin D. 

Since D is a fat soluble vitamin, dietary fat is needed to aid in its absorption. Low fat dieters are likely to be deficient in vitamin D. 

Sunscreen blocks the ability of the body to make vitamin D. As little as 10 minutes three times a week of sun exposure during summer months can improve D levels. Dark-skinned people are more likely to be D deficient as darker skin absorbs less sunlight. African –Americans generally have lower D blood levels and poorer health outcomes than Caucasians. 

The latitude where you live and time of year effects D levels. Those of us who reside north of a line drawn from Los Angeles through South Carolina don’t get enough sunlight at the right angle to ensure adequate vitamin D manufacture year round. A recent study found that teens living in Hawaii getting plenty of sun exposure still had low D levels. 

Consider the Following: 

  • Cancer cases increase as the distance from the Equator increases.

  • Type 1 diabetes is more common in countries where exposure to sunlight is lower.

  • Increasing cases of asthma especially in African-American kids may be the result of low D levels in mothers when pregnant.

  • Higher death rates from all causes and from cardiovascular disease double in men and women with below-average vitamin D levels.

  • Research has shown that women with blood levels of more than 52ng/ml have a 50% lower risk of breast cancer than those with blood levels of less than 10.

  • Research done on teens and young women in sunny California found a high prevalence of lower vitamin D levels and an association of higher BMI and abdominal fat than those with normal levels.

How to Measure Vitamin D 

Ask your doctor to order a 25(OH) D level. Currently the normal lab value is reported as 20-56 ng/ml or 50-140 nmol/l. Keep in mind that normal values are not optimal values. Optimal levels are often considered to be 30-50ng/ml although some practitioners aim for 60 ng/ml.  Any level below 32 ng/ml should be a red flag.

Once it has been determined that levels are too low, supplementation with D3 is the best approach to safely increasing your levels. Retesting blood levels should be done after 3 months of regular supplementation.

Doses and target levels should be individualized. FYI, toxic levels may occur when 25(OH) D levels exceed 100ng/ml. Toxicity can result in high blood calcium levels, anorexia, kidney stones, fever, vomiting, weight loss and pain. 

Until further and more definitive research clarifies therapeutic ranges discuss supplementation with your healthcare provider.  

In the coming year I’m sure we will continue to hear more on this long-neglected but vital nutrient. What is very clear now is that vitamin D should be tested on everyone as a part of a routine exam and dosing individualized based on lab values, health history and risk factors. 

 

The information presented on this site is in no way intended as medical advice or as a substitute for medical treatment. This information should be used in conjunction with the guidance and care of your physician. Consult your physician before beginning this program as you would any weight-loss or weight-maintenance program.  Those of you on diuretics or diabetes medication should proceed only under a doctor’s supervision as changing your diet usually requires a change in medication dosages. As with any plan, the weight-loss phases of this program should not be used by patients on dialysis or by pregnant or nursing women. As with any weight-loss plan, we recommend anyone under the age of 18 follow the program under the guidance of their physician.