Discover the power of vitamin and vitamin supplements for hair care

Vitamin D is most commonly associated with sunlight. Classified as a water-soluble vitamin, this nutrient acts more like a hormone. It is manufactured in the body when direct exposure to the ultraviolet rays of sunlight trigger compounds, similar in structure to cholesterol, to be synthesized by the liver and the kidneys into an active vitamin D substance called cholecalciferol. Vitamin D is also found in a few select food sources such as fortified milk and cereals, cod liver oil, egg yolks, liver, and fatty fish like salmon, tuna, mackerel, sardines and herring.

Most notably however, vitamin D is responsible for the absorption of calcium. In fact, the body cannot even absorb calcium in the absence of vitamin D. Vitamin D is key in the maintenance of calcium levels within the blood. It will encourage the absorption of the mineral from the intestines into the blood and as well, promote the removal of calcium form the bones into the blood.

Vitamin D also ensures regulation of calcium loss through the urine. Research shows that increased calcium absorption is directly related to increased bone strength and density, which can ultimately reduce the risk of osteoporosis. Scientists also know that a deficiency in vitamin D can result in such bone disorders as rickets, a condition that affects children and osteomalacia a similar condition affecting adults, both of which are characterized by lowered calcium deposits in the bones and weakened bone strength.

Numerous studies confirm that when combined with calcium, 200 IU per day vitamin D, supplement will increase bone density and work to prevent osteoporosis. One specific study where postmenopausal women were given 1000 mg of calcium and 500 IU of vitamin D supplement daily; had significant improvements in bone density, despite having inadequate blood levels of each prior to testing. In a similar study 240 healthy postmenopausal women who were given 900 mg per day of calcium and 200IU per day of vitamin D for two years, showed a notably reduced loss in calcium through the urine and a 2 percent increase in bone mineral density in their lumbar spine. This increase according to researchers, was highly significant.¹

There is also some research that suggests that less than 20 minutes of sunlight exposure per day could greatly reduce the risk of osteoporosis. It is also reported that skin pigment can affect the amount and duration of sunlight needed to produce vitamin D. For example, a person with dark skin will need three hours of sun exposure per week to meet their vitamin D requirements, while a fair-skinned person can get their vitamin D requirements by exposing their face and arms to bright sunlight for only 45 minutes per week.²

As well, sunscreen, clouds, windows, pollution and clothing can all affect the amount of ultraviolet rays actually getting through. It is also said that those people who live in New England and further north, have less available sunlight and in fact, in the winter months experience no vitamin D synthesis from the sun whatsoever. The guideline according to health professionals therefore, is if you cannot get at least 45 minutes of sunlight exposure per week, every week, which really is not that much, then you may need to take vitamin D supplements or a multivitamin that contains some vitamin D supplement.

In the winter some people also suffer form a condition called Seasonal Affective Disorder or SAD, in which the lack of sunlight causes sometimes severe depressive states. For the most part, this condition is treated with light therapy, but studies also suggest that vitamin D supplements may help to improve mood.³

A breakdown of cartilage in the joints has been associated with low levels of vitamin D. This condition often results in osteoarthritis, a painful condition that studies show vitamin D supplements may help to prevent. Studies and x-rays show that increased levels of vitamin D can also heal this type of degenerative process in the hips and joints of older women.⁴

Cancer is always a hot issue these days and vitamin D shows great promise in this area. Studies report that people who consume adequate amounts of Vitamin D, have a lowered risk of developing some types of cancer, including colon, prostate, breast and skin cancers. Calcium along with vitamin D in doses of 1800 mg per day and 800 IU per day respectively, have be shown to not only prevent but also treat colon cancer.⁵

As well a further study indicates that the same amounts of vitamin D, could drastically improve the survival rate of women suffering from breast cancer. A specific form of vitamin D is also reporting excellent results in cases of prostate cancer. According to researcher, sugars found in fruits (fructose) promote the production of this type of vitamin D, thereby further encouraging people to eat at least two servings of fruits each day.

The thyroid plays a significant role in the metabolism of calcium and phosphorus. Research shows that low levels of the thyroid hormone will also lead to low levels in these two minerals. Physicians will often prescribe vitamin D and calcium in cases of hypothyroidism (low thyroid activity). It has also been found however, that low levels of vitamin D can cause hyperthyroidism, an overactive thyroid gland. In this situation, the glands start to work overtime in order to increase more thyroid hormone to compensate for the lack in vitamin D. Treatment in this case is also vitamin D.⁶

Interesting studies now show that vitamin D may be directly related to type 1 diabetes. One study conducted in northern Finland where daylight exposure is somewhat limited, reported that babies who were given 2,000 IU daily of vitamin D (usually cod liver oil) for the first year, by the time they were 30, had a lowered risk of developing type 1 diabetes than those infants who were fed less vitamin D.7 This corresponds with information that shows that in the early 1960s, the recommended amount of vitamin D was as much as 5,000 IU per day in Finland. By 1964 however, it was lowered to 2,000 IU per day and then down to 1,000 IU per day in 1975 and finally to 400 IU per day in 1992. Consequently, since the 1980s, the incidences of type 1 diabetes have been on the incline.

Positive studies on the efficacy of vitamin D in such conditions as Multiple Sclerosis, high blood pressure, tuberculosis and atherosclerosis have also been noted. Research continues in these areas as in cases of skin disorders such as psoriasis, in which low levels of vitamin D are consistently reported.

Although too much sunlight or food sources is highly unlikely to result in dangerously elevated levels of vitamin D, supplements that are not taken according to recommended daily allowances may. Amounts in excess of 1,000 IU per day can cause an array of side effects including poor appetite, muscle problems, increased urination, excessive thirst, a metallic taste, weight loss, sore eyes, bone pain, vomiting, diarrhea or constipation and itchy skin.

Individuals who are already suffering from high phosphorus or calcium levels or who have heart or kidney problems should be cautious and speak with a health professional prior to taking vitamin D. Overdose of vitamin D can be decreased by such medications as antacids, calcium blockers, cholesterol-lowering drugs and anti-convulsants.

Vitamin D levels in the body can also be increased by estrogen in hormone replacements therapies, tuberculosis medications and diuretics.

Recently, the Food and Drug Administration (FDA) has mandated that weight loss products such as olestra and orlistat often added to many diet foods, also add extra vitamin A, E D and K, since these fat-soluble vitamins are adversely affected by the fat-binding properties of these products.

The recommended daily amounts of vitamin D are typically 400 IU or 10 mcg per day for men and 200 IU or 5 mcg per day for women. As we age however, the ability of the kidneys to convert vitamin D to its active form decreases, therefore it is very important to continue and as well, increase the amount of vitamin D accordingly. For instance, for a woman age 19 to 50, 200 IU per day is sufficient, however between the ages of 21 to 70, she should increase her intake to 400 IU per day and after 70, she should take 600 IU per day.

References:

1. Outila TA, Lamberg-Allardt CJ, “Ergocalciferol supplementation may positively affect lumbar spine bone mineral density of vegans”, J Am Diet Assoc, 2000 Jun;100(6):629.
2. Clemens TL, Adams JS, Henderson SL, Holick MF “Increased skin pigment reduces the capacity of skin to synthesise vitamin D3”, Lancet, 1982;1(8263):74-76.
3. Lansdowne AT, Provost SC, “Vitamin D3 enhances mood in healthy subjects during winter”, Psychopharmacology (Berl), 1998;135(4):319-323
4. Lane NE, Gore R, Cummings SR, et al “Serum vitamin D levels and incident changes of radiographic hip osteoarthritis, A longitudinal study”, Arthritis Rheum, 1999;42(5):854-860.
5. Langman M, Boyle P, et al, “Chemoprevention of colorectal cancer”, Gut, 1998;43:578–585
6. Pfeiffer M, Begerow B, Minne HW, Nachtigall D, Hansen C, “Effects of a short-term vitamin D(3) and calcium supplementation on blood pressure and parathyroid hormone levels in elderly women”, J Clin Endocrinol Metab, 2001;86(4):1633-1637.
7. Hypponen E, Laara E, Reunanen A, Jarvelin MR, Virtanen SM, “Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study”, Lancet, 2001;358(9292):1500-1503.