It is basic common knowledge to people today that they can get their recommended daily allowance (or RDA) of vitamin D (or calcium,) from milk and dairy products. However, this hasn’t always been the case.
In the 1930s, rickets were a huge health problem. Large numbers of children all across the United States were showing up to their doctors with severe cases of rickets, leading to spinal deformities later in life. Fortunately, the government stepped in. During the 1930s, a milk fortification program was put into play to help fight rickets. Today, rickets are an extremely rare illness that is no longer an issue.
Did you know that there are five different forms of vitamin D?
Vitamin D1 is compound of both lumisterol and ergocalciferol (vitamin D2)
Vitamin D2 – ergocalciferol. This is most commonly used to fortify foods.
Vitamin D3 – cholecalciferol. This particular vitamin is produced photochemically in the body after exposure to UVB rays.
Vitamin D4 – dihydroergocalciferol
Vitamin D5 – sitocalciferol.
In this article, we’ll be exploring the most common two forms of vitamin D which are D2 and D3.
Vitamin D2
Ergocalciferol, or vitamin D2, is generally obtained through milk and other fortified foods. It’s the most common of the D group, and it’s also the most important form for people. Vitamin D2 helps you maintain a normal level of calcium and phosphorus in your blood stream – which in turn helps prevent things like rickets, osteoporosis and osteomalacia.
Vitamin D2 can also be found in fish such as salmon, mackerel and tuna as well as eggs (particularly the egg yolks) and in fish liver oils such as cod liver oil. This is one of the few vitamins that do not occur commonly, which is one of the reasons our government implemented the milk fortification program way back in the day.
Vitamin D3
Vitamin D3 is obtained through exposure to sunlight. It finds its way into our body through synthesis in the skin in reaction to UVB, or sunlight. However, the amount of sunlight your body needs to produce this vitamin is directly related to the amount of melanin in your skin. Basically, the darker the skin – the more sunlight you actually need to produce the vitamin.
Vitamin D3 also comes in three forms: cholecalciferol, calcidiol, and calicitriol. While the three forms are produced in different parts of the body, all of them still occur after exposure to sunlight.
Deficiencies
Rickets
Rickets are one of the most common issues with children and vitamin D deficiency. Rickets is when the bones soften in a child’s body, leading to skeletal deformities and fractures. It is associated with a lack of vitamin D, as well as severe malnutrition. Some of the common skeletal deformities include bowed legs, knock-knees, or cranial, pelvic or spinal deformities.
Osteomalacia
Osteomalacia is the adult form of rickets. However, in adults it usually causes muscle weakness and weaker bones. Osteomalacia is when the bone becomes soft because of bone mineralization. Many of the symptoms may coincide with Osteoporosis; however they are two separate issues with the body.
Osteomalacia is more commonly found in darker skinned people who don’t receive quite enough sunlight. It can also be found in those who have a poor diet that is lacking in vitamin d or phosphorus.
Osteoporosis
Osteoporosis occurs when the bones in the body begin to lose their density, making them more prone to fractures. Osteoporosis is a disease that occurs after a lack of vitamin D (or calcium) over a longer period of time. It is estimated that 25 million or more adults in the US are at risk for developing this disease, or they may already have it.
Vitamin D in Excess
In addition to these three diseases, there are also side effects for taking too much vitamin D. Side effects include excess bone loss (due to the body being unable to process the extra calcium,) nausea, vomiting, weight loss or increased appetite, excessive urination, weakness, headaches, dry mouth or metallic taste, a ringing in the ears, fatigue and hypercalcaemia (an elevated level of calcium in the blood.)
Such side effects can be a signal that there is even more trouble brewing, as too much vitamin D intake can cause an impairment in kidney functions as well as calcium deposits in organs all over the body – including skin, kidneys and even inside the brain.
How do I prevent this?
Issues with bone density are most common among women, however surprisingly the recommended daily allowance (RDA) for both men and woman are exactly the same. Men and women aged 0 to 50 are recommended 5 micrograms (or 200 IU) each day. The amount of vitamin D recommended increases with age. Those in the 50 to 70 age bracket are recommended an intake of 10 micrograms (or 400 IU) each day, and those over 70 are told that 15 micrograms (or 600 IU) are required each day.
Pregnancy and Vitamin D
There is also no change in the recommended amount for women who are pregnant or lactating. However, your doctor may suggest an increase due to your personal health and/or family history, especially if any of the above mentioned diseases run in your family.
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Mayo Foundaction for Medical Education and Research, “Vitamin D
Office of Dietary Supplements, United States Government – “Dietary Supplement Fact Sheet
Wikipedia; “Osteomalacia”
Wikipedia; “Rickets”
Wikipedia; “Cholecalciferol”
Wikipedia; “Vitamin D”
