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How Much Vitamin D Is Enough?
Tweet Share on Facebook March 26, 2010 Comment (24)I've been hearing a lot about vitamin D lately. My multivitamin has 400 IU, but I've heard reports that the recommended daily allowance is not actually high enough. What do you think?
Our bodies make vitamin D3 when we're exposed to sunlight. (This substance is more appropriately considered a hormone because it's synthesized in one location for use in other parts of the body.)We know that vitamin D increases absorption of calcium from the intestinal tract. It also stimulates osteoblasts that remodel bone, making good healthy bone. Newer evidence suggests that vitamin D plays a regulatory role in controlling panels of genes that affect our immune systems. Higher vitamin D levels are associated with a lower risk of adult onset type 2 diabetes and autoimmune inflammatory responses against one's own thyroid gland, resulting in an underactive thyroid. D3 deficiency may be related to a number of other autoimmune disorders in which we attack a number of our own cells and glands. Vitamin D may play some role in preventing infection and in warding off cancer.
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How Much Calcium Do Americans Need?
Tweet Share on Facebook March 16, 2010 Comment (5)Are Americans getting enough calcium? I've heard that health officials here may recommend more calcium than is necessary. How much do people really need?
Calcium is an essential nutrient, but the optimal intake is an unsettled issue. For adults over 50, the definition of adequate intake in the United States is 1,200 milligrams per day; in the United Kingdom, this is 700 milligrams per day; and the World Health Organization, looking at the same data, concluded that 500 milligrams per day is adequate. The primary justification for high consumption of calcium has been prevention of osteoporosis and fractures, and much of the disagreement is due to the use in the United States of short-term studies of calcium deposition in bones to set the value for adequate calcium intake. Long-term studies do not support benefits of high intake of calcium or milk in preventing fracture risk. The WHO conclusions were influenced by the observation that most adults worldwide consume little or no dairy products, have calcium intakes below 500 milligrams per day, and tend to have lower rates of fractures than we do in America and Europe, where calcium and milk intake are relatively high. -
Does Aromatherapy Offer Health Benefits? Unlikely
Tweet Share on Facebook March 16, 2010 Comment (9)
Aromatherapy may make you feel better, but there's no good evidence of any solid health benefits to date. Our laboratory conducted a very elaborate and detailed study to look at the effects of lavender and lemon oils on mood, heart rate and blood pressure, stress hormones, and immune function. Lemon did in fact enhance positive moods, but neither lemon nor lavender had any positive effects on the participants' physiology or biochemical markers over a period of several hours. In one part of the study, participants had their foot immersed in ice water for a minute; their pain ratings when they were smelling distilled water were no different from when they were inhaling the lavender or lemon scents. A group of British researchers reported that men and women who placed their hand and forearm in ice water for up to 15 minutes reported more pain when the ambient odor was either pleasant (lemon) or unpleasant (machine oil) compared to a no-odor condition. And Florida researchers who used heat and pressure pain found that none of their odors (lavender, rosemary, and distilled water) were related to how much pain participants reported. The absence of any analgesic benefits across all three studies is notable, because pain reduction is a primary reason for aromatherapy's widespread use in health-related applications ranging from labor pain to post-surgical discomfort.
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