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The influence of dietary supplementation with moderate (200 mg/day) and high (2,000 mg/day) doses of vitamin C on serum lipid levels was studied in 27 female long-stay hospital patients characterized by low plasma ascorbic acid levels during the preceding year. The two doses of vitamin C were compared with placebo in a double-blind, cross-over design during randomly determined 6-week periods followed by 2-week washout intervals. No effect was observed on serum cholesterol, HDL cholesterol, and triglyceride levels. Plasma ascorbic acid levels were highly significantly increased (p < 0.001) by both doses of vitamin C. It is concluded that dietary supplementation with moderate or high doses of vitamin C does not affect serum lipids of persons who have low plasma ascorbic acid levels suggestive of possible marginal deficiency of vitamin C.

The reactivity of the chick embryo erythron to varying ambient oxygen concentrations was investigated. The hemoglobin (Hb) concentration, the hematocrit and red cell count were determined in embryos incubated in 40 % O2, air and 15 % O2. The age of the embryos varied between 9 and 19 days. The results indicated that embryos weighing less than 7 g and approximately less than 14 days old do not increase their Hb, hematocrit or erythrocyte count when exposed to 15 % O2. In embryos aged 16 days or over the 15 % O2 exerts a stimulatory effect: the Hb and hematocrit values exceed those found in the embryos incubated in 40 % O2. The mean corpuscular volume and the mean corpuscular Hb are not affected by differences in ambient oxygen concentrations. It is pointed out that the 15th day of incubation seems to represent a critical phase in chick embryo development—it is not only approximately the date when myeloid erythropoiesis begins to dominate, but also the date when, for instance, some polyamines begin to be synthetized and the hypophysis becomes functionally active.