Cancer Support Community would like to thank Dr. Avery for all of his time and efforts on the wonderful educational programs he's presented for our participants over the years and send Dr Avery and his wife Carol best wishes on their upcoming move out of state!
Vitamin D in Health and Disease Robert Avery MD, FACP
Good habits are essential to good health, don’t smoke, exercise, and follow a good diet full of fruits and vegetables while limiting animal fat and red meat. Supplemental vitamins have not been found to prevent any diseases and the American Heart Association and the American Cancer Society both recommend against taking supplemental anti-oxidant vitamins. They recommend a good diet, but what about vitamin D?
What is vitamin D?
It is not a vitamin at all but a secosteroid hormone that is essential for bone health and for the prevention of many other diseases. Only certain foods contain vitamin D, these include fatty fish and supplemented dairy products. The best source of vitamin D is the SUN.
The sun is a very efficient way to get vitamin D. The figure demonstrates how vitamin D is made.
Vitamin D is essential for bone health and calcium absorption from the gut. It helps maintain blood calcium and phosphorus levels and promotes normal mineralization of bone (strong bones) and is necessary for bone growth and remodeling.
Vitamin D toxicity
Too much vitamin D causes symptoms related to hypercalcemia; anorexia, nausea, vomiting, constipation, confusion, polyuria, polydipsia, kidney failure. This rarely occurs with vitamin D tablets but you need doses of 50,000 IU daily for weeks to months.
A level of 30ng/mL is necessary to prevent Rickets and 200 ng/mL is toxic. What about > 30 and < 200? Vitamin D receptors are found on multiple organs and tissues throughout the body and higher blood levels are needed to prevent disease.
Disease and Geography
Studies have revealed an increased risk of multiple sclerosis in northern zones. In Europe, MS is rare at the equator, but more than cases/100,000 are found between latitude 44 ° and 64 °. In the US, many more cases are found over the 37 ° latitude.
Colon, lung, breast and prostate cancers increase in incidence going from equator north AND, patients from southern latitudes have improved survival compared to northern latitudes.
Autoimmune disease, type I diabetes, heart disease and hypertension are all more common in northern climates and patients have fewer MS exacerbations in the summer months. MS exacerbations and MS plaques peak about 2 months after the lowest sun exposure months i.e. winter. Cyclic exacerbations suggest a link with sun exposure and vitamin D production.
Blood levels of vitamin D
There are data to suggest that many diseases are associated with low vitamin D levels such as osteoporosis, heart disease, hypertension, cancers, type I diabetes, multiple sclerosis. Others suggest a link with chronic fatigue, chronic pain, autism, and muscle weakness.
What affects vitamin D levels?
These factors affect vitamin D levels; residence (south vs midwest/north), season (summer/autumn vs winter/spring), race (white vs Afr Amer/Asian), BMI, pregnancy, and breast feeding.
Light skin may require only 15 minutes of sun to get adequate vitamin D, dark skin can require up to 10 X exposure.
Vitamin D is a fat soluble vitamin; others include vitamins A, E, and K. The more adipose present, the more vitamin D will be stored and not available.
Many pregnant women are low in vitamin D. A study in the Netherlands found 8% light skinned and 80% Turkish women were vit D deficient (Am J Clin Nutr 2006;84:350). Another US study demonstrated 80% Afr Amer and 50% of Euro Amer had low vitamin D levels during pregnancy (University of Pittsburgh Schools of the Health Sciences (2007, March 10). Vitamin D Deficiency Widespread During Pregnancy).
Implications for the Mother; five-fold increased risk of pre-eclampsia and a doubled C-Sxn rate, implications for the baby; increased risk of rickets, DM I, MS, heart disease, hypertension.
Breast feeding is best. It enhances the immune system, protects against allergies, decreases childhood obesity, increases cognitive function, reduces heart disease and increases baby-mother bonding, BUT there is not enough vitamin D in breast milk. Some argue that bottle feeding is better for this reason. The American Academy of Pediatrics encourages vitamin D supplementation for breast fed infants.
It only stands to reason that the breast milk will also be vitamin D deficient. Increase mother’s vitamin D intake AND presto! breast milk vitamin D increases as well.
We need more vitamin D for good health so we need more SUN. PROBLEM! More than 1 million non-melanoma skin cancers are diagnosed each year (Amer Ca Soc), 60,000 cases of melanoma each year with deaths accounting for 2700 for non-melanoma skin cancers, and 8000 for melanoma skin cancers.
Risks for skin cancer include; sun exposure, fair skin color, exposure to coal tar, pitch, creosote, arsenic, or radium, family history, and presence of multiple moles.
Expose to 25% of the time needed to cause light redness to the skin; 5-10 minutes for very light skin, 10-15 minutes for light skin, 30-60 minutes for darker skin. This will produce a blood produce 15-20,000 IU of vitamin D. Only a few days a week is all that is necessary.
OR, if sun exposure is not available, you have a history of sun damage or skin cancer already or a family history of skin cancer; Take oral vitamin D3, 1000-4000 IU daily. You can verify correct dose with a blood level if you wish.
Vitamin D is not just for bones anymore. It is very important in preventing many diseases. There are misconceptions and misinformation about vitamin D and the sun. Both the public and physicians need education in this area.