VIT D
Here is what I pulled up on Vitamin D for you... Hope it helps!
Prolonged exclusive breastfeeding without the AAP-recommended vitamin D supplementation is a significant cause of rickets, particularly in dark-skinned infants breastfed by mothers who are not vitamin D replete [6]. Additional causes of rickets include extensive use of sunscreens and placement of children in daycare programs, where they often have less outdoor activity and sun exposure [29,38]. Rickets is also more prevalent among immigrants from Asia, Africa, and the Middle East, possibly because of genetic differences in vitamin D metabolism and behavioral differences that lead to less sun exposure
In adults, vitamin D deficiency can lead to osteomalacia, resulting in weak muscles and bones [7,8,15]. Symptoms of bone pain and muscle weakness can indicate inadequate vitamin D levels, but such symptoms can be subtle and go undetected in the initial stages.
People with fat malabsorption
As a fat-soluble vitamin, vitamin D requires some dietary fat in the gut for absorption. Individuals who have a reduced ability to absorb dietary fat might require vitamin D supplements [46]. Fat malabsorption is associated with a variety of medical conditions including pancreatic enzyme deficiency, Crohn's disease, cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease [15].
People who are obese
Individuals with a body mass index (BMI) ≥30 typically have a low plasma concentration of 25(OH)D [47]; this level decreases as obesity and body fat increase [48]. Obesity does not affect skin's capacity to synthesize vitamin D, but greater amounts of subcutaneous fat sequester more of the vitamin and alter its release into the circulation. Even with orally administered vitamin D, BMI is inversely correlated with peak serum concentrations, probably because some vitamin D is sequestered in the larger pools of body fat [47].
In March 2007, a group of vitamin D and nutrition researchers published a controversial and provocative editorial contending that the desirable concentration of 25(OH)D is ≥30 ng/mL (≥75 nmol/L) [12]. They noted that supplemental intakes of 400 IU/day of vitamin D increase 25(OH)D concentrations by only 2.8-4.8 ng/mL (7-12 nmol/L) and that daily intakes of approximately 1,700 IU are needed to raise these concentrations from 20 to 32 ng/mL (50 to 80 nmol/L).
Osteoporosis
More than 25 million adults in the United States have or are at risk of developing osteoporosis, a disease characterized by fragile bones that significantly increases the risk of bone fractures [50]. Osteoporosis is most often associated with inadequate calcium intakes (generally <1,000-1,200 mg/day), but insufficient vitamin D contributes to osteoporosis by reducing calcium absorption [51]. Although rickets and osteomalacia are extreme examples of the effects of vitamin D deficiency, osteoporosis is an example of a long-term effect of calcium and vitamin D insufficiency [52]. Adequate storage levels of vitamin D maintain bone strength and might help prevent osteoporosis in older adults, nonambulatory individuals who have difficulty exercising, postmenopausal women, and individuals on chronic steroid therapy [53].
Normal bone is constantly being remodeled. During menopause, the balance between these processes changes, resulting in more bone being resorbed than rebuilt. Hormone therapy with estrogen and progesterone might be able to delay the onset of osteoporosis. However, some medical groups and professional societies recommend that postmenopausal women consider using other agents to slow or stop bone resorption because of the potential adverse health effects of hormone therapy [54-56].
Most supplementation trials of the effects of vitamin D on bone health also include calcium, so it is not possible to isolate the effects of each nutrient. The authors of a recent evidence-based review of research concluded that supplements of both vitamin D3 (at 700-800 IU/day) and calcium (500-1,200 mg/day) decreased the risk of falls, fractures, and bone loss in elderly individuals aged 62-85 years [6]. The decreased risk of fractures occurred primarily in elderly women aged 85 years, on average, and living in a nursing home. Women should consult their healthcare providers about their needs for vitamin D (and calcium) as part of an overall plan to prevent or treat osteoporosis.
African Americans have lower levels of 25(OH)D than Caucasians, yet they develop fewer osteoporotic fractures. This suggests that factors other than vitamin D provide protection [57]. African Americans have an advantage in bone density from early childhood, a function of their more efficient calcium economy, and have a lower risk of fracture even when they have the same bone density as Caucasians. They also have a higher prevalence of obesity, and the resulting higher estrogen levels in obese women might protect them from bone loss [57]. Further reducing the risk of osteoporosis in African Americans are their lower levels of bone-turnover markers, shorter hip-axis length, and superior renal calcium conservation. However, despite this advantage in bone density, osteoporosis is a significant health problem among African Americans as they age [57].
Cancer
Laboratory and animal evidence as well as epidemiologic data suggest that vitamin D status could affect cancer risk. Strong biological and mechanistic bases indicate that vitamin D plays a role in the prevention of colon, prostate, and breast cancers. Emerging epidemiologic data suggest that vitamin D has a protective effect against colon cancer, but the data are not as strong for a protective effect against prostate and breast cancer, and are variable for cancers at other sites [58-59]. Studies do not consistently show a protective effect or no effect, however. One study of Finnish smokers, for example, found that subjects in the highest quintile of baseline vitamin D status have a three-fold higher risk of developing pancreatic cancer [60].
Vitamin D emerged as a protective factor in a prospective, cross-sectional study of 3,121 adults aged ≥50 years (96% men) who underwent a colonoscopy. The study found that 10% had at least one advanced cancerous lesion. Those with the highest vitamin D intakes (>645 IU/day) had a significantly lower risk of these lesions [61]. However, the Women's Health Initiative, in which 36,282 postmenopausal women of various races and ethnicities were randomly assigned to receive 400 IU vitamin D plus 1,000 mg calcium daily or a placebo, found no significant differences between the groups in the incidence of colorectal cancers over 7 years [62]. More recently, a clinical trial focused on bone health in 1,179 postmenopausal women residing in rural Nebraska found that subjects supplemented daily with calcium (1,400-1,500 mg) and vitamin D3 (1,100 IU) had a significantly lower incidence of cancer over 4 years compared to women taking a placebo [63]. The small number of cancers reported (50) precludes generalizing about a protective effect from either or both nutrients or for cancers at different sites. This caution is supported by an analysis of 16,618 participants in NHANES III, where total cancer mortality was found to be unrelated to baseline vitamin D status [64]. However, colorectal cancer mortality was inversely related to serum 25(OH)D concentrations; levels >80 nmol/L were associated with a 72% risk reduction than those <50 nmol/L.
Further research is needed to determine whether vitamin D inadequacy in particular increases cancer risk, whether greater exposure to the nutrient is protective, and whether some individuals could be at increased risk of cancer because of vitamin D exposure [58].
Other conditions
A growing body of research suggests that vitamin D might play some role in the prevention and treatment of type 1 [65] and type 2 diabetes [66], hypertension [67], glucose intolerance [68], multiple sclerosis [69], and other medical conditions [70-71]. However, most evidence for these roles comes from in vitro, animal, and epidemiological studies, not the randomized clinical trials considered to be more definitive. Until such trials are conducted, the implications of the available evidence for public health and patient care will be debated.
A recent meta-analysis found that use of vitamin D supplements was associated with a reduction in overall mortality from any cause by a statistically significant 7% [72-73]. The subjects in these trials were primarily healthy, middle aged or elderly, and at high risk of fractures; they took 300-2,000 IU/day of vitamin D supplements.
Excessive sun exposure does not result in vitamin D toxicity because the sustained heat on the skin is thought to photodegrade previtamin D3 and vitamin D3 as it is formed [11,30]. High intakes of dietary vitamin D are very unlikely to result in toxicity unless large amounts of cod liver oil are consumed; toxicity is more likely to occur from high intakes of supplements.
Long-term intakes above the UL increase the risk of adverse health effects [5] (Table 4). Substantially larger doses administered for a short time or periodically (e.g., 50,000 IU/week for 8 weeks) do not cause toxicity. Rather, the excess is stored and used as needed to maintain normal serum 25(OH)D concentrations when vitamin D intakes or sun exposure are limited [15,76].
Steroids
Corticosteroid medications such as prednisone, often prescribed to reduce inflammation, can reduce calcium absorption [77-79] and impair vitamin D metabolism. These effects can further contribute to the loss of bone and the development of osteoporosis associated with their long-term use [78-79].
Other medications
Both the weight-loss drug orlistat (brand names Xenical® and alli™) and the cholesterol-lowering drug cholestyramine (brand names Questran®, LoCholest®, and Prevalite®) can reduce the absorption of vitamin D and other fat-soluble vitamins [80-81]. Both phenobarbital and phenytoin (brand name Dilantin®), used to prevent and control epileptic seizures, increase the hepatic metabolism of vitamin D to inactive compounds and reduce calcium absorption [82].
The Dietary Guidelines for Americans describes a healthy diet as one that
Vitamin D Deficiency
Nutrient deficiencies are usually the result of dietary inadequacy, impaired absorption and use, increased requirement, or increased excretion. A vitamin D deficiency can occur when usual intake is lower than recommended levels over time, exposure to sunlight is limited, the kidneys cannot convert vitamin D to its active form, or absorption of vitamin D from the digestive tract is inadequate. Vitamin D-deficient diets are associated with milk allergy, lactose intolerance, and strict vegetarianismProlonged exclusive breastfeeding without the AAP-recommended vitamin D supplementation is a significant cause of rickets, particularly in dark-skinned infants breastfed by mothers who are not vitamin D replete [6]. Additional causes of rickets include extensive use of sunscreens and placement of children in daycare programs, where they often have less outdoor activity and sun exposure [29,38]. Rickets is also more prevalent among immigrants from Asia, Africa, and the Middle East, possibly because of genetic differences in vitamin D metabolism and behavioral differences that lead to less sun exposure
In adults, vitamin D deficiency can lead to osteomalacia, resulting in weak muscles and bones [7,8,15]. Symptoms of bone pain and muscle weakness can indicate inadequate vitamin D levels, but such symptoms can be subtle and go undetected in the initial stages.
People with fat malabsorption
As a fat-soluble vitamin, vitamin D requires some dietary fat in the gut for absorption. Individuals who have a reduced ability to absorb dietary fat might require vitamin D supplements [46]. Fat malabsorption is associated with a variety of medical conditions including pancreatic enzyme deficiency, Crohn's disease, cystic fibrosis, celiac disease, surgical removal of part of the stomach or intestines, and some forms of liver disease [15].
People who are obese
Individuals with a body mass index (BMI) ≥30 typically have a low plasma concentration of 25(OH)D [47]; this level decreases as obesity and body fat increase [48]. Obesity does not affect skin's capacity to synthesize vitamin D, but greater amounts of subcutaneous fat sequester more of the vitamin and alter its release into the circulation. Even with orally administered vitamin D, BMI is inversely correlated with peak serum concentrations, probably because some vitamin D is sequestered in the larger pools of body fat [47].
Vitamin D and Health
Optimal serum concentrations of 25(OH)D for bone and general health throughout life have not been established [6,11] and are likely to vary at each stage of life, depending on the physiological measures selected. The three-fold range of cut points that have been proposed by various experts, from 16 to 48 ng/mL (40 to 120 nmol/L), reflect differences in the functional endpoints chosen (e.g., serum concentrations of parathyroid hormone or bone fractures), as well as differences in the analytical methods used. The numerous assays for 25(OH)D provide differing results. One reason for these issues of precision and variability is that no standard reference preparations or calibrating materials are available commercially to help reduce the variability of results between methods and laboratories. Efforts are underway to standardize the quantification of 25(OH)D to measure vitamin D status.In March 2007, a group of vitamin D and nutrition researchers published a controversial and provocative editorial contending that the desirable concentration of 25(OH)D is ≥30 ng/mL (≥75 nmol/L) [12]. They noted that supplemental intakes of 400 IU/day of vitamin D increase 25(OH)D concentrations by only 2.8-4.8 ng/mL (7-12 nmol/L) and that daily intakes of approximately 1,700 IU are needed to raise these concentrations from 20 to 32 ng/mL (50 to 80 nmol/L).
Osteoporosis
More than 25 million adults in the United States have or are at risk of developing osteoporosis, a disease characterized by fragile bones that significantly increases the risk of bone fractures [50]. Osteoporosis is most often associated with inadequate calcium intakes (generally <1,000-1,200 mg/day), but insufficient vitamin D contributes to osteoporosis by reducing calcium absorption [51]. Although rickets and osteomalacia are extreme examples of the effects of vitamin D deficiency, osteoporosis is an example of a long-term effect of calcium and vitamin D insufficiency [52]. Adequate storage levels of vitamin D maintain bone strength and might help prevent osteoporosis in older adults, nonambulatory individuals who have difficulty exercising, postmenopausal women, and individuals on chronic steroid therapy [53].
Normal bone is constantly being remodeled. During menopause, the balance between these processes changes, resulting in more bone being resorbed than rebuilt. Hormone therapy with estrogen and progesterone might be able to delay the onset of osteoporosis. However, some medical groups and professional societies recommend that postmenopausal women consider using other agents to slow or stop bone resorption because of the potential adverse health effects of hormone therapy [54-56].
Most supplementation trials of the effects of vitamin D on bone health also include calcium, so it is not possible to isolate the effects of each nutrient. The authors of a recent evidence-based review of research concluded that supplements of both vitamin D3 (at 700-800 IU/day) and calcium (500-1,200 mg/day) decreased the risk of falls, fractures, and bone loss in elderly individuals aged 62-85 years [6]. The decreased risk of fractures occurred primarily in elderly women aged 85 years, on average, and living in a nursing home. Women should consult their healthcare providers about their needs for vitamin D (and calcium) as part of an overall plan to prevent or treat osteoporosis.
African Americans have lower levels of 25(OH)D than Caucasians, yet they develop fewer osteoporotic fractures. This suggests that factors other than vitamin D provide protection [57]. African Americans have an advantage in bone density from early childhood, a function of their more efficient calcium economy, and have a lower risk of fracture even when they have the same bone density as Caucasians. They also have a higher prevalence of obesity, and the resulting higher estrogen levels in obese women might protect them from bone loss [57]. Further reducing the risk of osteoporosis in African Americans are their lower levels of bone-turnover markers, shorter hip-axis length, and superior renal calcium conservation. However, despite this advantage in bone density, osteoporosis is a significant health problem among African Americans as they age [57].
Cancer
Laboratory and animal evidence as well as epidemiologic data suggest that vitamin D status could affect cancer risk. Strong biological and mechanistic bases indicate that vitamin D plays a role in the prevention of colon, prostate, and breast cancers. Emerging epidemiologic data suggest that vitamin D has a protective effect against colon cancer, but the data are not as strong for a protective effect against prostate and breast cancer, and are variable for cancers at other sites [58-59]. Studies do not consistently show a protective effect or no effect, however. One study of Finnish smokers, for example, found that subjects in the highest quintile of baseline vitamin D status have a three-fold higher risk of developing pancreatic cancer [60].
Vitamin D emerged as a protective factor in a prospective, cross-sectional study of 3,121 adults aged ≥50 years (96% men) who underwent a colonoscopy. The study found that 10% had at least one advanced cancerous lesion. Those with the highest vitamin D intakes (>645 IU/day) had a significantly lower risk of these lesions [61]. However, the Women's Health Initiative, in which 36,282 postmenopausal women of various races and ethnicities were randomly assigned to receive 400 IU vitamin D plus 1,000 mg calcium daily or a placebo, found no significant differences between the groups in the incidence of colorectal cancers over 7 years [62]. More recently, a clinical trial focused on bone health in 1,179 postmenopausal women residing in rural Nebraska found that subjects supplemented daily with calcium (1,400-1,500 mg) and vitamin D3 (1,100 IU) had a significantly lower incidence of cancer over 4 years compared to women taking a placebo [63]. The small number of cancers reported (50) precludes generalizing about a protective effect from either or both nutrients or for cancers at different sites. This caution is supported by an analysis of 16,618 participants in NHANES III, where total cancer mortality was found to be unrelated to baseline vitamin D status [64]. However, colorectal cancer mortality was inversely related to serum 25(OH)D concentrations; levels >80 nmol/L were associated with a 72% risk reduction than those <50 nmol/L.
Further research is needed to determine whether vitamin D inadequacy in particular increases cancer risk, whether greater exposure to the nutrient is protective, and whether some individuals could be at increased risk of cancer because of vitamin D exposure [58].
Other conditions
A growing body of research suggests that vitamin D might play some role in the prevention and treatment of type 1 [65] and type 2 diabetes [66], hypertension [67], glucose intolerance [68], multiple sclerosis [69], and other medical conditions [70-71]. However, most evidence for these roles comes from in vitro, animal, and epidemiological studies, not the randomized clinical trials considered to be more definitive. Until such trials are conducted, the implications of the available evidence for public health and patient care will be debated.
A recent meta-analysis found that use of vitamin D supplements was associated with a reduction in overall mortality from any cause by a statistically significant 7% [72-73]. The subjects in these trials were primarily healthy, middle aged or elderly, and at high risk of fractures; they took 300-2,000 IU/day of vitamin D supplements.
Health Risks from Excessive Vitamin D
Vitamin D toxicity can cause nonspecific symptoms such as nausea, vomiting, poor appetite, constipation, weakness, and weight loss [74]. More seriously, it can also raise blood levels of calcium, causing mental status changes such as confusion and heart rhythm abnormalities [8]. The use of supplements of both calcium (1,000 mg/day) and vitamin D (400 IU/day) by postmenopausal women was associated with a 17% increase in the risk of kidney stones over 7 years in the Women's Health Initiative [75]. Deposition of calcium and phosphate in the kidneys and other soft tissues can also be caused by excessive vitamin D levels [5]. A serum 25(OH)D concentration consistently >200 ng/mL (>500 nmol/L) is considered to be potentially toxic [15]. In an animal model, concentrations ≤400 ng/mL (≤1,000 nmol/L) were not associated with harm [16].Excessive sun exposure does not result in vitamin D toxicity because the sustained heat on the skin is thought to photodegrade previtamin D3 and vitamin D3 as it is formed [11,30]. High intakes of dietary vitamin D are very unlikely to result in toxicity unless large amounts of cod liver oil are consumed; toxicity is more likely to occur from high intakes of supplements.
Long-term intakes above the UL increase the risk of adverse health effects [5] (Table 4). Substantially larger doses administered for a short time or periodically (e.g., 50,000 IU/week for 8 weeks) do not cause toxicity. Rather, the excess is stored and used as needed to maintain normal serum 25(OH)D concentrations when vitamin D intakes or sun exposure are limited [15,76].
Interactions with Medications
Vitamin D supplements have the potential to interact with several types of medications. A few examples are provided below. Individuals taking these medications on a regular basis should discuss vitamin D intakes with their healthcare providers.Steroids
Corticosteroid medications such as prednisone, often prescribed to reduce inflammation, can reduce calcium absorption [77-79] and impair vitamin D metabolism. These effects can further contribute to the loss of bone and the development of osteoporosis associated with their long-term use [78-79].
Other medications
Both the weight-loss drug orlistat (brand names Xenical® and alli™) and the cholesterol-lowering drug cholestyramine (brand names Questran®, LoCholest®, and Prevalite®) can reduce the absorption of vitamin D and other fat-soluble vitamins [80-81]. Both phenobarbital and phenytoin (brand name Dilantin®), used to prevent and control epileptic seizures, increase the hepatic metabolism of vitamin D to inactive compounds and reduce calcium absorption [82].
Vitamin D and Healthful Diets
According to the 2005 Dietary Guidelines for Americans, "nutrient needs should be met primarily through consuming foods. Foods provide an array of nutrients and other compounds that may have beneficial effects on health. In certain cases, fortified foods and dietary supplements may be useful sources of one or more nutrients that otherwise might be consumed in less than recommended amounts. However, dietary supplements, while recommended in some cases, cannot replace a healthful diet."The Dietary Guidelines for Americans describes a healthy diet as one that
- Emphasizes a variety of fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.
- Milk is fortified with vitamin D, as are many ready-to-eat cereals and a few brands of yogurt and orange juice. Cheese naturally contains small amounts of vitamin D.
- Includes lean meats, poultry, fish, beans, eggs, and nuts.
- Fish such as salmon, tuna, and mackerel are very good sources of vitamin D. Small amounts of vitamin D are also found in beef liver and egg yolks.
- Is low in saturated fats, trans fats, cholesterol, salt (sodium), and added sugars.
- Vitamin D is added to some margarines.
- Stays within your daily calorie needs.
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My Citracal Petites have Vitamin D...I'm taking 4 to 6 of them a day. I had a deficiency in one or the other pre-op, so they had me up the dosage. They're pretty small and easy to swallow - just a pain to remember to take them at separate times from my other vitamins...
Good Luck!
John
Good Luck!
John
Citracal® Petites with Vitamin D
- One serving provides 400 mg of calcium
- One serving provides 400 IU of Vitamin D
Serving Size : 2 tablets
DIRECTIONS FOR USE: Take 1 to 2 tablets two times daily or as recommended by your physician, pharmacist or health professional.
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