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Vitamin D3


Due to a low vitamin D level (17,7ug/l, the recommended value would be 20), my doctor has ordered me (43 years old) to take vitamin D (8 dr.) in addition to the multivitamins I take in the mornings. However, during the time I take the drops, I get cramps in the fingers and toes as well as between the ribs, which are becoming painful with time. A change in dosage did not help. As soon as I stop the vitamin D, the cramps get better. I have tried several times over the years and it has always been the same. My doctor does not know why this is happening. Is it possible that it has to do with the changing calcium level, and how can I avoid this?

Many thanks for your efforts and kind regards.

vitamin D (cholecalciferol) is undisputed in combination with calcium in osteoporosis treatment. The body can produce vitamin D itself with sufficient exposition to sunlight. Via the autocrine function, it affects cell differentiation, cell proliferation and immunomodulation. Vitamin D deficit affects the calcium balance via parathormone. Vitamin D and calcium deficits have been described in adult CF patients, leading to an increased osteoporosis rate. Since apparently you are having a side effect when taking vitamin D drops, you should try taking vitamin D tablets under the assumption, that other agents in the drops are responsbile for it. The dosage should be 1000i IU. In this context, you should also check your electrolyte (sodium, potassium, calcium, magnesium), thyroid gland hormones, and parathormone levels. In addition, there is also the question about your respiratory situation, since hypocapnia leads to disturbances in the acid-base metabolism, whose symptoms can include cramps.

I would discuss these different possibilities with your treating doctor.

Kind regards,
Christian von Mallinckrodt